| Snoddy, Oliver, see also Ó Snodaigh, PádraigÓ Snodaigh, Pádraig, see also Snoddy, Oliver | Cross-reference | | |
| "A great and deserved name" : commemorating Cromwell | Morrill, John Stephen, 1946- | Article in Journal | | 1999 |
| "A great battle" - Bishop James A. Goold of Melbourne (1848-1864) | Martin, F. X. (Francis Xavier), 1922-2000 | Article in Book | NA | 1986 |
| "An endless line of useless hills" : in memoriam Thomas Slattery | Mahon, Oliver | Article in Journal | | 2002 |
| "The family piece” :
Oliver Goldsmith and the politics of the everyday in eighteenth-century domestic portraiture | Flint, Christopher | Article in Journal | | 1995 |
| "The harp new-strung" : nationalism, culture and the United Irishmen | Stewart, Anthony Terence Quincey, 1929-2010 | Article in Book | NA | 1986 |
| "When they persecute you in one state, flee ye to another" : petition to Pope Pius the Ninth by potential Irish emigrants to Brazil | | Article in Journal | | 2006 |
| 'A statue's there to mark the place'. Cú Chulainn in the GPO | Tracy, Robert | Article in Journal | | 2008 |
| 'Eternity is not long enough nor hell hot enough...' The Catholic Church and Fenianism | Rafferty, Oliver P. | Article in Journal | | 2008 |
| 'I do wish we were not the "Ulster" division but just the 36th' | Mitchell, Pauline | Article in Journal | | 2014 |
| 'Pirates in our channel': The Cromwellian navy in Ireland, 1649-53 | Murphy, Elaine | Article in Journal | | 2011 |
| 'Shipped for the Barbadoes': Cromwell and the Irish migration to the Caribbean | O Siochrú, Micheál | Article in Journal | | 2008 |
| 'Studies' and the shadow of Modernism | Rafferty, Oliver P. | Article in Journal | | 2011 |
| 'The Deserted Village' and Goldsmith's social doctrines | Bell, Howard J | Article in Journal | | 1944 |
| 'The Dream Gone Bust' : Irish Responses to Emigration 1922-60 | Travers, Pauric | Article in Book | | 1989 |
| 'What did I die of?': the deaths of Parnell, Wilde... and other literary pathologies | Lyons, J. B. (John Benignus) | Monograph or Collective Volume | | 1991 |
| 1798, 1898 and the political implications of Sheppard's monuments | Turpin, John | Article in Journal | | 1998 |
| 1916 Government Propaganda | Snoddy, Oliver | Article in Journal | | 1973 |
| 1917 in Ireland - in dungeons deep | Snoddy, Oliver | Article in Journal | | 1967 |
| 1917 in Ireland - three by-elections of 1917 | Snoddy, Oliver | Article in Journal | | 1967 |
| A baking stone from Fermanagh | Davies, OliverEvans, E. Estyn (Emyr Estyn), 1905-1989 | Article in Journal | | 1942 |
| A bishop of the penal times : being letters and reports of John Brenan, bishop of Waterford (1671-93) and archbishop of Cashel (1677-93) | | Monograph or Collective Volume | Cork UP | 1932 |
| A captain at large in the province : impressions of Northern Ireland 1968-9 | Reynolds, Oliver | Article in Journal | | 1990 |
| A Clan na Gael constitution and ritual from Portland, 1916 | Snoddy, Oliver | Article in Journal | | 1970 |
| A Galway lawyer at the Confederation of Kilkenny (Richard Martin Fitz Oliver of Dun Guaire, c. 1602-1648) | Martyn, Adrian | Monograph or Collective Volume | | 2005 |
| A Gogarty/Gregory correspondence 1910-30 | Lyons, J. B. (John Benignus) | Article in Book | | 2000 |
| A Gogarty/Gregory correspondence, 1910-30 | Lyons, J. B. (John Benignus) | Article in Journal | | 1997 |
| A history of Dunshaughlin, Culmullen and Knockmark | Coogan, Oliver | Monograph or Collective Volume | The author | 1989 |
| A history of Irish emigration during the great famine | Mac Donough, Oliver O.G. | Thesis | | 1946 |
| A history of the diocese of Cork : from reformation to the penal era | Bolster, Evelyn | Monograph or Collective Volume | Tower Books | 1982 |
| A history of the Pathological Society of Great Britain and Ireland | Dible, J. Henry | Monograph or Collective Volume | Oliver & Boyd | 1957 |
| A new history of Cromwell's Irish campaign | McKeiver, Philip G. | Monograph or Collective Volume | Advance Press | 2007 |
| A Pattern of Government Growth, 1800-60 : the Passenger Acts and their Enforcement | MacDonagh, Oliver | Monograph or Collective Volume | | 1961 |
| A perspective upon historical process : the case of southern Irish Unionism | D'Alton, Ian | Article in Book | NA | 1990 |
| A previously unnoticed letter of Oliver Plunkett | | Article in Journal | | 1975 |
| A school photograph examined | Mahon, Oliver | Article in Journal | | 1994 |
| A Scramble for Ireland: Cromwell and the Land Settlement | Cunningham, John, 1984- | Article in Book | NA | 2021 |
| A seagrey house : the history of Renvyle House | Lidwill, J. A. | Monograph or Collective Volume | [s.n.] | 1988 |
| A short history of Ireland | Ranelagh, John O'Beirne | Monograph or Collective Volume | Cambridge University Press | 1983 |
| A star was born in my brother's band | Tobin, Oliver, 1940- | Monograph or Collective Volume | Choice Publishing | 2009 |
| A summary of the archaeology of Ulster, 2 | Davies, Oliver | Article in Journal | | 1949 |
| A summary of the archaeology of Ulster, part 1 | Davies, Oliver | Article in Journal | | 1948 |
| A sword for Christ : the republican era in Great Britain and Ireland | Cobb, Jonathan | Monograph or Collective Volume | Birlinn | 2021 |
| A tale of adversity and survival: manuscripts touching Gragans Castle | O'Loghlen, EdwardO'Loghlen, Michael | Article in Journal | | 2017 |
| Accusations of Oliver Plunkett | Mooney, Canice | Article in Journal | | 1956 |
| After the civil wars | Mortimer, Sarah | Article in Journal | | 2012 |
| Ambiguity in nationalism - the case of Ireland | MacDonagh, Oliver | Article in Journal | | 1981 |
| Ambiguity in nationalism : the case of Ireland | MacDonagh, Oliver | Article in Book | | 1994 |
| Ambiguity in nationalism—the case of Ireland | Macdonagh, Oliver | Article in Journal | | 1981 |
| American Catholicism and the Irish from colonial times to 1870 | Rafferty, Oliver P. | Article in Book | | 2024 |
| An account of the life of Captain Samuel Jervois (c.1620-1694) | Jervois, William | Article in Journal | | 2009 |
| An appeal of the Ulster Franciscans against Blessed Oliver Plunket | Jennings, Brendan | Article in Journal | | 1956 |
| An Australian Prime Minister in Ireland : R.G. Menzies, 1941 | Martin, Allan | Article in Book | | 1990 |
| An Australian Prime Minister in Ireland : R.G.Menzies, 1941 | Martin, Allan | Article in Book | NA | 1990 |
| An Irish-American friendship : the justice and the nationalist historian | Cosgrove, Richard A. | Article in Journal | | 1986 |
| An unholy dispute. The controversy surrounding the appointment of Oliver Kelly to the See of Tuam 1809-1814 | Waldron, Liam | Article in Journal | | 2005 |
| An unpublished letter of St Oliver Plunkett | | Article in Journal | | 1975 |
| An unrecognized extract from the 'South English Legendary' | Pickering, Oliver S. | Article in Journal | | 1972 |
| Antiquities of Inch island, Co. Donegal | Davies, OliverSwan, H. P. | Article in Journal | | 1938 |
| Apologia Pro Vita Sua : in vita mea vademecum | MacDonagh, Oliver | Article in Book | | 1990 |
| Appointments to the Restoration Irish bench | Dennehy, Coleman A. | Article in Book | Four Courts Press | 2020 |
| Archbishop Oliver Plunkett : Ireland's first canonized martyr | Curtayne, Alice | Article in Journal | | 1976 |
| Arthur Jacob | Somerville-Large, L. B. | Article in Book | | 1952 |
| As I was going down Sackville Street | Gogarty, Oliver St John | Monograph or Collective Volume | O'Brien Press | 1994 |
| Aspects of English rule in Ireland | Snoddy, Oliver | Article in Journal | | 1970 |
| Athlone level crossing control centre | Doyle, Oliver | Article in Journal | | 2007 |
| Athlone level crossing control centre | Doyle, Oliver | Article in Journal | | 2007 |
| Aughentaine castle | Davies, Oliver | Article in Journal | | 1939 |
| Augustus Saint-Gaudens | Snoddy, Oliver | Article in Journal | | 1971 |
| Australia's role in Ireland's Declaration of a Republic and withdrawal from the Commonwealth 1948-9 | Quirke, Noel | Article in Book | | 1989 |
| Australia, Britain, Ireland and the Ottawa Conference : the Empire at Work | O'Brien, John B. | Article in Book | | 1989 |
| Ballynascree church and legends | Davies, Oliver | Article in Journal | | 1941 |
| Bangor Abbey, county Down | Davies, Oliver | Article in Journal | | 1946 |
| Bantry station fire 1954 | Doyle, Oliver | Article in Journal | | 2017 |
| Beaufield and its people | O'Connor, Anne | Article in Journal | | 2016 |
| Benedict Fearon (1924-2020): Appreciation and Homily [By Fr Oliver Brennan] | | Article in Journal | | 2021 |
| Bernard Shaw's other island | Gibbs, A. M. | Article in Book | | 1983 |
| Bibliography of periodical literature relating to the archaeology of Ulster, 1940 | Davies, Oliver | Article in Journal | | 1942 |
| Biographical propriety and the historical Asquith | Hazelhurst, Cameron | Article in Book | | 1990 |
| Bishop John Brenan, the intimate of Blessed Oliver | Power, P. | Article in Book | | 1937 |
| Bishops and violence : a response to Oliver Rafferty | Donnelly, Peter | Article in Journal | | 1994 |
| Blessed Bishop John Brenan, the intimate of Blessed Oliver | Power, P., Canon | Article in Book | | 1937 |
| Blessed Oliver and the Benedictines | Phillipson, Wulstan | Article in Book | | 1937 |
| Blessed Oliver Plunket | O'Connor, R. F. | Article in Journal | | 1924 |
| Blessed Oliver Plunket | MacLeod, Catriona | Article in Journal | | 1939 |
| Blessed Oliver Plunket and the Popish Plot in Ireland | Walker, Breifne | Article in Journal | | 1968 |
| Blessed Oliver Plunket. Historical studies | Anonymous | Monograph or Collective Volume | | 1937 |
| Blessed Oliver Plunkett | Curtis, Emmanuel | Monograph or Collective Volume | Clonmore & Reynolds | 1963 |
| Blessed Oliver Plunkett : historical studies | Various authors | Monograph or Collective Volume | Gill | 1937 |
| Blessed Oliver Plunkett and his Irish Jesuit schools | Corcoran, Timothy Joseph, 1872-1943 | Article in Journal | | 1941 |
| Blessed Oliver Plunkett and the tories | Mac Phóil, Donnchadha | Article in Journal | | 1959 |
| Blessed Oliver Plunkett in Down and Connor | Smyth, J. | Article in Journal | | 1937 |
| Blessed Oliver Plunkett's report on the diocese of Armagh, 1670 | | Article in Journal | | 1959 |
| Blessed Oliver's relics at Goodings | Francis, Agnes | Article in Journal | | 1969 |
| Bolting horses | Doyle, Oliver | Article in Journal | | 2011 |
| Boyhood memories | O'Neill, Willie Oliver, Rev. | Article in Journal | | 1998 |
| Brazil in British and Irish archives | Marshall, Oliver | Monograph or Collective Volume | University of Oxford | 2002 |
| Brethren in Christ : Frederick Lucas and social Catholicism in Ireland | Maume, Patrick | Article in Book | | 2013 |
| Bridges - Dublin border | Doyle, Oliver | Article in Journal | | 1996 |
| Bungling British diplomacy : notes on Irish, Cypriot, Egyptian and Indian history | Snoddy, Oliver | Article in Journal | | 1973 |
| Burke, Goldsmith and the Irish absentees | Griffin, Michael J. | Article in Book | | 2006 |
| Burke, Ireland and the Empire | Beckett, J. C. (James Camlin) | Article in Book | | 1983 |
| Cardinal Cullen, early Fenianism, and the MacManus funeral affair | Rafferty, Oliver P. | Article in Journal | | 1995 |
| Cardinal Cullen, early Fenianism, and the MacManus funeral affair | Rafferty, Oliver P. | Article in Journal | | 1995 |
| Carleton's ecclesiastical context : the Ulster Catholic experience | Rafferty, Oliver P. | Article in Journal | | 2000 |
| Carnteel church | Davies, Oliver | Article in Journal | | 1941 |
| Castlecaulfield church, parish of Donaghmore (Co. Tyrone) | Burges, AlfredDavies, Oliver | Article in Journal | | 1938 |
| Catholic and Protestant relations in Derry in the episcopacy of Charles O'Donnell 1798-1823 | Rafferty, Oliver P. | Article in Book | | 1999 |
| Catholic Unionism, a case study : Sir Denis Stanislaus Henry (1864-1925) | Phoenix, Éamon | Article in Book | | 2013 |
| Catholic-Christian identity and modern Irish poetry | O'Donoghue, Bernard | Article in Book | | 2013 |
| Catholicism in county Fermanagh, 1795-1850 | Rafferty, Oliver P. | Article in Book | | 2004 |
| Catholicism in the North of Ireland since 1891 | Rafferty, Oliver P. | Article in Book | | 1995 |
| Catholicism in Ulster, 1603-1983 : an interpretative history | Rafferty, Oliver P. | Monograph or Collective Volume | Gill & Macmillan | 1994 |
| Cecil King : a legacy of painting | Dowling, Oliver | Article in Journal | | 2008 |
| Celtic Christianity : texts and representations | Davies, Oliver | Article in Book | | 2002 |
| Charles Gavan Duffy in Australia | Parnaby, J. E. | Article in Book | | 1983 |
| Charles Lucas | Fleetwood, John | Article in Book | | 1952 |
| Chronicle. Events to mark the 350th anniversary of Str Oliver Plunkett as Archbishop of Armagh | | Article in Journal | | 2019 |
| Chronicle. Events to mark the 350th anniversary of Str Oliver Plunkett as Archbishop of Armagh | | Article in Journal | | 2019 |
| Church and State, and Nationalism in Ireland | Rafferty, Oliver P. | Article in Book | Oxford University Press | 2003 |
| Church architecture in Ulster | Davies, Oliver | Article in Journal | | 1944 |
| Civil autonomy and military power in early modern Ireland | Ó Siochrú, Micheál | Article in Journal | | 2011 |
| Civil Wars and Interregnum | Morrill, John | Article in Book | Oxford University Press | 2023 |
| Clanna Gael-Fontenoy : the history of Dublin's G.A.A. club. Vol. 1 (1887-1950) | Hogan, Oliver | Monograph or Collective Volume | Cumann Clanna Gael/Fontenoy G.A.A. Club | 1994 |
| Clanna Gael/Fontenoy : the history of Dublin's GAA club. Vol 1 : 1887-1950 | Hogan, Oliver | Monograph or Collective Volume | Clanna Gael/Fontenoy GAA Club | 1995 |
| Clientelism, Community and Collaboration: Loyalism in Nineteenth-Century Colonial India | Godsmark, OliverGould, William | Article in Book | | 2014 |
| Clogher crosses and other curved stones | Davies, Oliver | Article in Journal | | 1938 |
| Clouds of glory | MacDonagh, Oliver | Article in Book | | 2003 |
| Coin-hoards from Ulster | Davies, OliverSkillen, J. | Article in Journal | | 1942 |
| Collected works of Oliver Goldsmith. 5 vols. | | Monograph or Collective Volume | | 1966 |
| Collections towards illustrating the biography of Scotch, English and Irish members, S[ocietatis] J[esu] | Oliver, G. | Monograph or Collective Volume | | 1838 |
| Collegeland or the Manor of Slatmulrooney | McCaffrey, Oliver | Article in Journal | | 2014 |
| Conclusion. Settling and unsettling Ireland : the Cromwellian and Williamite revolutions | Barnard, T. C. (Toby Christopher) | Article in Book | | 1995 |
| Contributions to the study of crannogs in south Ulster | Davies, Oliver | Article in Journal | | 1942 |
| Contributions to the study of crannogs in south Ulster | Davies, Oliver | Article in Journal | | 2013 |
| Cork-Cobh re-signalling | Doyle, Oliver | Article in Journal | | 2010 |
| County Donegal railways joint committee railcars | Doyle, Oliver | Article in Journal | | 2011 |
| County Longford explored : Irish history in the hidden heartland | O'Ferrall, Fergus | Monograph or Collective Volume | Geography Publications | 2025 |
| County map of Queen's | Sloane, Oliver | Monograph or Collective Volume | | 1764 |
| Court-Castle faction and the Irish viceroyalty : the appointment of Oliver St John as Lord Deputy of Ireland in 1616 | Rutledge, V. L. | Article in Journal | | 1989 |
| Cromwell | Howell, Roger | Monograph or Collective Volume | | 1977 |
| Cromwell | Cottret, Bernard | Monograph or Collective Volume | Fayard | 1992 |
| Cromwell | Lapie, P.-O. | Monograph or Collective Volume | | 1949 |
| Cromwell : a paradox | Dalton, Noel | Article in Journal | | 1972 |
| Cromwell : an honourable enemy. The untold story of the Cromwellian invasion of Ireland | Reilly, Tom | Monograph or Collective Volume | Brandon | 1999 |
| Cromwell : our chief of enemies | McElligott, Jason, 1972- | Monograph or Collective Volume | Dundalgan Press | 1994 |
| Cromwell : portrait of a soldier | Gillingham, J. B. | Monograph or Collective Volume | | 1976 |
| Cromwell : the Irish question | Reilly, Tom | Article in Journal | | 2012 |
| Cromwell and Catholics : towards a reassessment of lay Catholic experience in Interregnum Ireland | Spurlock, R. Scott | Article in Book | | 2010 |
| Cromwell and Crumlin | O'Connor, Patrick | Article in Journal | | 1950 |
| Cromwell and English liberty | Howell, Roger | Article in Book | | 1986 |
| Cromwell and Ireland | Brown, R. N. | Article in Journal | | 1957 |
| Cromwell and Ireland before 1649 | Little, Patrick, 1969- | Article in Book | | 2009 |
| Cromwell and Ireland: New Perspectives | | Monograph or Collective Volume | Liverpool University Press | 2021 |
| Cromwell and Ireland: new perspectives; edited by Martyn Bennett, Ray Gillespie, R. Scott Spurlock, | Ó Siochrú, Micheál | Article in Journal | | 2021 |
| Cromwell and Plunkett : two early modern heads called Oliver | Tarlow, Sarah | Article in Book | | 2013 |
| Cromwell and the Interregnum | Smith, David L. (David Lawrence), 1963- | Monograph or Collective Volume | Blackwell Publishers | 2003 |
| Cromwell at Drogheda : a reply to Mr. J.B. Williams | Murray, R. H. | Article in Journal | | 1912 |
| Cromwell at Drogheda, 1649 | Simms, J. G. (John Gerald) | Article in Journal | | 1973 |
| Cromwell at Drogheda, 1649 | Simms, J. G. (John Gerald) | Article in Journal | | 1974 |
| Cromwell at Drogheda. Some new light on old faces | Matthews, Brendan | Article in Journal | | 2012 |
| Cromwell in Callan | Kennedy, Joseph | Article in Journal | | 1984 |
| Cromwell in Ireland | Wheeler, James Scott | Monograph or Collective Volume | Gill & Macmillan | 1999 |
| Cromwell in Ireland : a history of Cromwell's Irish campaign | Murphy, Denis | Monograph or Collective Volume | | 1883 |
| Cromwell in Ireland : the massacres | Faul, Denis | Article in Journal | | 2004 |
| Cromwell was framed : Ireland 1649 | Reilly, Tom | Monograph or Collective Volume | Chronos Books | 2014 |
| Cromwell's generals | Ashley, Maurice Percy | Monograph or Collective Volume | Jonathan Cape | 1954 |
| Cromwell's influence on the great landowners of east Waterford | Shanahan, Mary | Article in Book | | 2005 |
| Cromwell, de Brendan Kennelly : el humor negro como exorcismo | Villacañas, Beatriz | Article in Journal | | 2003 |
| Cromwell, Drogheda, and the abuse of Irish history | McElligott, Jason, 1972- | Article in Journal | | 2001 |
| Cromwell, la revolution d'Angleterre et la guerre civile | Poussou, Jean-Pierre | Monograph or Collective Volume | Presses Universitaries de France | 1993 |
| Cromwell, Scotland and Ireland | Stevenson, David, Ph. D. | Article in Book | | 1990 |
| Cromwellian courts martial records | McElligott, Jason | Article in Journal | | 2012 |
| Cromwellian England 1649-1660 | Worden, Blair | Article in Book | | 1986 |
| Cromwellian Ireland : English government and reform in Ireland, 1649-1660 | Barnard, T. C. (Toby Christopher) | Monograph or Collective Volume | Clarendon Press | 2000 |
| Cromwellian Transplantations of the Irish to the Colonies | Coburn, Heidi J. | Article in Book | | 2021 |
| Daniel Mannix and the cult of personality | Griffin, J. | Article in Book | | 1986 |
| Data : What is known about the Irish in North America? | Akenson, Donald Harman | Article in Book | | 1986 |
| Davide Moriarty's episcopal leadership in the diocese of Kerry, 1854-77 | Rafferty, Oliver P. | Article in Book | NA | 2020 |
| Davy's island church, lower Lough Erne | Davies, Oliver | Article in Journal | | 1938 |
| Dean Richardson's further account of com. Cavan | Davies, OliverGaffikin, M.Paterson, T.G.F. | Article in Journal | | 2013 |
| Deane's western architectural gems | Murphy, Oliver | Article in Journal | | 2011 |
| Death comes to the archbishop | Dempsey, Anthony | Article in Journal | | 1939 |
| Derryloran church | Davies, Oliver | Article in Journal | | 1942 |
| Difflin Lake railway | Doyle, Oliver | Article in Journal | | 2011 |
| Divided conquerors : the Rump Parliament, Cromwell's army and Ireland | Cunningham, John, 1984- | Article in Journal | | 2014 |
| Docklands, a new Dublin terminus | Doyle, Oliver | Article in Journal | | 2009 |
| Documents and sources. The Cheney letters, 1682-85 | Dudley, Rowena | Article in Journal | | 1996 |
| Domhnach Mór, 5 : The Cromwellian settlement and its aftermath | Ó Doibhlín, A. É. | Article in Journal | | 1961 |
| Donagh church, Co. Monaghan | Davies, OliverGaffikin, M.Paterson, T. G. F. | Article in Journal | | 1939 |
| Double track on the Midland | Doyle, Oliver | Article in Journal | | 2001 |
| Drakestown graveyard, Co. Meath | Davies, Oliver | Article in Journal | | 1941 |
| Drogheda Grammar School | McCormack, Christopher | Article in Journal | | 2016 |
| Drogheda remodelling | Doyle, Oliver | Article in Journal | | 1997 |
| Drumcondra | Doyle, Oliver | Article in Journal | | 1998 |
| Drumswords church, county Monaghan | Davies, Oliver | Article in Journal | | 1938 |
| Duelling - a point of honour. Part 1 | Murphy, Oliver | Article in Journal | | 2010 |
| Dungiven priory | Davies, Oliver | Article in Journal | | 1939 |
| Dunleer | Doyle, Oliver | Article in Journal | | 1996 |
| Easter Rising commemorations in the early Irish State | Martin, Allison | Article in Journal | | 2016 |
| Eccentric Ireland. Co. Longford | Sharkey, Olive | Article in Journal | | 2010 |
| Ecclesiastical remains in Co. Cavan | Davies, Oliver | Article in Journal | | 1940 |
| Editorial note|Abbreviations | | Article in Journal | | 2013 |
| Edmund Murphy, Oliver Plunkett and the Popish Plot | Gibney, John, 1976- | Article in Journal | | 2004 |
| Emigration and the state, 1833-55 : an essay in administrative history | MacDonagh, Oliver | Article in Journal | | 1955 |
| Emigration from Ireland to Australia : an overview | MacDonagh, Oliver | Article in Book | | 1986 |
| Emigration from Ireland to New South Wales in the Mid-Nineteenth Century | Reid, Richard | Article in Book | | 1989 |
| Engine factory sidings, Dublin, Wicklow and Wexford railway | Doyle, Oliver | Article in Journal | | 2001 |
| English, Irish and Irish-American pioneer settlers in nineteenth-century Brazil | Marshall, Oliver | Monograph or Collective Volume | University of Oxford. Centre for Brazilian Studies | 2005 |
| English-speaking communities in Latin America | | Monograph or Collective Volume | Macmillan | 2000 |
| Envoi : humanity, economy, policy : on common sense and expertise in the life of Sir Jeremiah Fitzpatrick | MacDonagh, Oliver | Article in Book | NA | 1988 |
| Evolutionary by design | McBrinn, Joseph | Article in Journal | | 2011 |
| Excavation of a crannog at Deredis Upper, in Lough Inchin, Co. Cavan | Davies, Oliver | Article in Journal | | 1946 |
| Excavation of a crannog at Deredis Upper, in Lough Inchin, co. Cavan | Davies, Oliver | Article in Journal | | 2013 |
| Excavations around Lough Eske, Co. Donegal | Davies, Oliver | Article in Journal | | 1946 |
| Excavations at Inishee | Davies, Oliver | Article in Journal | | 1940 |
| Excavations at Island Mac Hugh | Davies, Oliver | Article in Journal | | 1952 |
| Excavations at the south gate of the Dorsey entrenchment | Davies, Oliver | Article in Journal | | 1940 |
| Exporting state and nation : English institutions and English identity in medieval Ireland | Frame, Robin | Article in Book | | 2005 |
| Extracts - New Zealand | Oliver, John | Article in Journal | | 1984 |
| F.S. Oliver, Alexander Hamilton, and the "American Plan" for resolving Britain's constitutional crises, 1903-1921 | Fair, John D. | Article in Journal | | 1999 |
| F.S. Oliver, Lord Selborne and Federalism | Boyce, David George, 1942-Stubbs, J. O. | Article in Journal | | 1976 |
| Fact or Fiction? Cromwell in Dublin 1649 | Ní Murchadha, Maighréad | Article in Journal | | 2011 |
| Faisnéis faoi Oilibhéar Ó Ceallaigh, ardeaspag Thuama, 1815-1834 | Ó Tuairisg, P. | Article in Journal | | 1980 |
| Family of Mary Catherine Caraher and Bernard Woods, Keady | Woods J. Oliver | Article in Journal | | 1987 |
| Father Luke Wadding's work for the education of the Irish clergy | Cleary, Gregory | Article in Book | | 1937 |
| Father Mathew's statue : the making of a monument in Cork | Inglis, Kenneth Stanley | Article in Book | | 1986 |
| Female alliances in Cromwellian Ireland: the social and political network of Elizabeth Butler, marchioness of Ormonde | McAreavey, Naomi | Article in Journal | | 2021 |
| Fenian flags | Snoddy, Oliver | Article in Journal | | 1967 |
| Fenianism in North America in the 1860s : problems for church and state | Rafferty, Oliver P. | Article in Journal | | 1999 |
| Finland, Norway and the Easter Rising | Griffiths, A. R. G. | Article in Book | | 1983 |
| Folklore in Maghera parish | Davies, Oliver | Article in Journal | | 1945 |
| Forced and unforced rape in early Irish law | Oliver, Lisi | Article in Journal | | 1993 |
| Forging a shared identity : Irish migrants and steel cities, 1850-1900 | Betts, Oliver | Article in Book | | 2018 |
| French bishops' mission to Ireland, October 1916 | O'Hanlon, Oliver | Article in Journal | | 2016 |
| Fresh light on Cromwell at Drogheda | Williams, Joseph Batterson [i.e. Muddiman, Joseph George] | Article in Journal | | 1912 |
| From Irish exceptionalism to European normality: The new Islamic presence in the Republic of Ireland | Scharbrodt, Oliver | Article in Journal | | 2014 |
| From Reformation to Restoration : Ireland 1534-1660 | Canny, Nicholas P. | Monograph or Collective Volume | Helicon | 1987 |
| From the bridge to the abyss | Snoddy, Oliver | Article in Journal | | 1972 |
| From Tuam to Ballyspellan | Ó Fearghail, Feargus | Article in Journal | | 1987 |
| GAA football finals, 1953-54 | Doyle, Oliver | Article in Journal | | 1994 |
| Gaelic and Catholic in the early middle ages | Maier, Bernhard | Article in Book | | 2013 |
| Gaelic Catholicism and the Ulster plantation | Gillespie, Raymond | Article in Book | | 2013 |
| General Nugent and the Ulster Division in the March 1918 retreat | Perry, Nicholas | Article in Journal | | 1999 |
| George Russell at the Oriel's 21st anniversary | Nulty, OliverRussell, George | Monograph or Collective Volume | Oriel Gallery | 1989 |
| George Tyrrell and Catholic modernism | | Monograph or Collective Volume | Four Courts | 2012 |
| Gleanings from Irish history | Butler, W. F. T. (William Francis Thomas), 1869-1930 | Monograph or Collective Volume | | 1925 |
| Glounthaune-Midleton re-opening | Doyle, Oliver | Article in Journal | | 2009 |
| God's executioner : Oliver Cromwell and the conquest of Ireland | Ó Siochrú, Micheál | Monograph or Collective Volume | Faber | 2008 |
| God's general : Cromwell the soldier | Robbins, Simon | Monograph or Collective Volume | Sutton | 2003 |
| God’s Wall of Brass: Cromwell’s Generals in Ireland, 1649–1650 | Bennett, Martyn | Article in Book | | 2021 |
| Goethe's estimate of Oliver Goldsmith | Hammer, Carl I. | Article in Journal | | 1945 |
| Going to the wars : experience of the British civil wars, 1638-1651 | Carlton, Charles Hope | Monograph or Collective Volume | | 1992 |
| Goldsmith : interviews and recollections | | Monograph or Collective Volume | St. Martin's Press | 1993 |
| Goldsmith and Steele's 'Englishman' | Friedman, Arthur | Article in Journal | | 1940 |
| Goldsmith and the chain of being | Lynskey, Winifred | Article in Journal | | 1945 |
| Goldsmith's 'Natural history' - a plan | Jones, Claude E. | Article in Journal | | 1946 |
| Goldsmith's ancestry : fact and tradition | Murray, P. | Article in Book | | 1980 |
| Goldsmith's contributions to the 'Critical Review' | Friedman, Arthur | Article in Journal | | 1946 |
| Gormanstown & Laytown viaducts | Doyle, Oliver | Article in Journal | | 1996 |
| Governing the police | Finnane, Mark | Article in Book | | 1990 |
| Grafting Ireland onto Australia | Windsor, G. | Article in Book | | 1983 |
| Great Britain and Ireland, 1760-1800 : a study in political administration | | Monograph or Collective Volume | Oliver & Boyd | 1963 |
| Greystones | Doyle, Oliver | Article in Journal | | 1999 |
| Guinness, 1886-1939 : from corporation to the Second World War | Dennison, S. R.MacDonagh, Oliver | Monograph or Collective Volume | Cork University Press | 1998 |
| Hell or Connaught! : the Cromwellian settlement of Ireland, 1652-1660 | Ellis, Peter Berresford, 1943- | Monograph or Collective Volume | Blackstaff Press | 1988 |
| Henry (William) Oliver 1807-1888 : ancestry and descendents | Rea, Henry Oliver | Monograph or Collective Volume | Tyrone Printing Co. | 1959 |
| Henry Fitzsimon, the Irish Jesuits and Catholic identity in the early modern period | Jackson, Brian | Article in Book | | 2013 |
| Henry Ireton | Ramsey, R. W. | Monograph or Collective Volume | Longmans | 1949 |
| Henry Ireton in Ireland, 1649–1651: Oliver Cromwell’s ‘Second Self’? | Farr, David | Article in Book | | 2021 |
| Heraldry in St Peter's R.C. Church, West Street, Drogheda | Bellew, Séamus | Article in Journal | | 2014 |
| Heroic poetry from the book of the dean of Lismore | | Monograph or Collective Volume | Oliver & Boyd | 1939 |
| Historical geology of Ireland | Charlesworth, J. K. | Monograph or Collective Volume | Oliver & Boyd | 1963 |
| Historical sketches of the ancient native Irish and their descendants; illustrative of their past and present state with regard to literature, education, and oral instruction | Anderson, Christopher, 1782-1852 | Monograph or Collective Volume | Oliver & Boyd | 1828 |
| History of Clonmel | Burke, William P. | Monograph or Collective Volume | | 1907 |
| History of Drogheda up to date | Hughes, Anne | Monograph or Collective Volume | Old Drogheda Society | 2003 |
| Holmes and Denning : two 20th-century legal icons compared | Hogan, Gerard | Article in Journal | | 2007 |
| How it began, what might have been? political memoirs of Northern Ireland in the 1960s | Mulholland, Marc | Article in Journal | | 2018 |
| I follow Saint Patrick | Gogarty, Oliver St John | Monograph or Collective Volume | Rich & Cowan | 1938 |
| Ideas and institutions, 1830-1845 | MacDonagh, Oliver | Article in Book | | 1989 |
| Identity and political fragmentation in independent Ireland, 1923-83 | Fuller, Louise | Article in Book | | 2013 |
| Imagination and revolution : the Chuchulain myth | Rafroidi, Patrick | Article in Book | | 1983 |
| International peace keeping - the Irish experience | MacDonald, Oliver A. K. | Article in Journal | | 1995 |
| Introduction | Rafferty, Oliver P. | Article in Book | | 2014 |
| Introduction | Rafferty, Oliver P. | Article in Book | | 2013 |
| Introduction (Drogheda and Wexford, 1649) | Reilly, Tom | Article in Book | | 2021 |
| Introduction : Ireland and the Union, 1801-1870 | MacDonagh, Oliver | Article in Book | | 1989 |
| Introduction. Oliver Davies (1905-1986) | Barry, Terence B. | Article in Journal | | 2013 |
| Ireland | MacDonagh, Oliver | Monograph or Collective Volume | Prentice Hall | 1968 |
| Ireland : the union and its aftermath | MacDonagh, Oliver ;McCormack, W. J. | Monograph or Collective Volume | University College Dublin | 2003 |
| Ireland : the Union and its aftermath. | MacDonagh, Oliver | Monograph or Collective Volume | Allen & Unwin | 1977 |
| Ireland and Britain's second application to join the EEC | Toomey, Jane | Article in Book | | 2003 |
| Ireland and Irish-Australia : studies in cultural and political history | | Monograph or Collective Volume | Croom Helm | 1986 |
| Ireland and Irish-Australia : studies in cultural and political history | | Monograph or Collective Volume | | 1986 |
| Ireland and Irish-Australia : Studies in Cultural and Political History | | Monograph or Collective Volume | | 1986 |
| Ireland and the Paris peace conference 1919 | Snoddy, Oliver | Article in Journal | | 1969 |
| Ireland and the union, 1801-70 | MacDonagh, Oliver | Article in Book | | 1989 |
| Ireland as precursor! Jebb's concept of colonial nationalism and the crisis of Anglo-Irish relations in the era of revolution, 1775-1783 | MacDonagh, Oliver | Article in Book | | 1988 |
| Ireland's army medical service | McKinney, T. | Article in Book | | 1952 |
| Ireland, England and Australia : essays in honour of Oliver MacDonagh | | Monograph or Collective Volume | Cork University Press | 1990 |
| Ireland, from the Flight of the Earls to Grattan's Parliament, 1607-1782; a documentary record | | Monograph or Collective Volume | | 1951 |
| Ireton's siege of Waterford, July-August 1650 | McCarthy, Patrick | Article in Journal | | 2020 |
| Irish booksellers and English writers 1740-1800 | Cole, R. C. | Monograph or Collective Volume | Mansell | 1986 |
| Irish Catholic culture in the nineteenth century : a study in perjury | Edwards, Owen Dudley | Article in Book | | 2013 |
| Irish Catholic identities | | Monograph or Collective Volume | Manchester University Press | 2013 |
| Irish Catholics and the bible in the nineteenth century | Rafferty, Oliver P. | Article in Book | | 2013 |
| Irish Culture and Nationalism Translated : St Patrick's Day in Australia, 1888 | MacDonagh, Oliver | Article in Book | | 1983 |
| Irish culture and nationalism translated : St Patrick's Day, 1888 in Australia | MacDonagh, Oliver | Article in Book | | 1983 |
| Irish culture and nationalism, 1750-1950 | | Monograph or Collective Volume | Macmillan | 1983 |
| Irish diaspora Catholicism in North America | Doyle, David | Article in Book | | 2013 |
| Irish emigration to the United States of America and the British colonies during the famine | MacDonagh, Oliver | Article in Book | | 1994 |
| Irish emigration to the United States of America and the British colonies during the famine | MacDonagh, Oliver | Article in Book | | 1956 |
| Irish history | MacDonagh, Oliver | Article in Book | | 1953 |
| Irish identity and the future of Catholicism | Coll, Niall | Article in Book | | 2013 |
| Irish images of Cromwell | Barnard, T. C. (Toby Christopher) | Article in Book | | 1993 |
| Irish influence on early Saxon orthographic practices | Oliver, Lisi | Article in Journal | | 1994 |
| Irish medals | Cresswell, Oliver | Monograph or Collective Volume | The author | 1963 |
| Irish medical links with the continent | Hayes, Richard Francis | Article in Book | | 1952 |
| Irish nationalism and culture 1750-1950 | | Monograph or Collective Volume | Macmillan | 1983 |
| Irish nationalism and the British Empire in the late nineteenth century | Brasted, H. V. (Howard V.) | Article in Book | | 1983 |
| Irish Nationalism and the British Empire in the Late Nineteenth Century | Brasted, H. V. (Howard V.) | Article in Book | | 1983 |
| Irish Organs and Reversible Nationalism : the Irish-Australian and Irish Australia, 1894-5 | McLachlan, Noel | Article in Book | | 1989 |
| Irish political Catholicism from the 1530s to 1660 | Finnegan, David | Article in Book | | 2013 |
| Irish priests transported under the Commonwealth | | Article in Journal | | 1949 |
| Irish rail signalling | Doyle, Oliver | Article in Journal | | 2003 |
| Irish revolutionary nationalism : Tone to Pearse | Oliver, Seán | Article in Book | | 1993 |
| Irish undercurrents of the politics of April 1653 | Barber, Sarah | Article in Journal | | 1992 |
| Irish-Australian studies : papers delivered at the fifth Irish-Australian Conference | MacDonagh, OliverMandle, William Frederick | Monograph or Collective Volume | | 1989 |
| Irish-language sources for Irish Catholic identity since the early modern period : a brief survey | Ó Ciardha, Éamonn | Article in Book | | 2013 |
| Is Leaving Cert history fit for purpose? | Leighton, Oliver | Article in Journal | | 2014 |
| Island of saints and scholars : myth or reality? | Ó Corráin, Donnchadh | Article in Book | | 2013 |
| Jesuit Finances in Restoration Ireland: a relational network analysis | Foerster, Martin
| Article in Journal | | 2021 |
| John Milton's student, Richard Barry : a biographical note | Taaffe, J. G. | Article in Journal | | 1962 |
| Journals and letters : Vol.3, 1910-15, Vol. 4,1916-30 | Esher, Oliver, ViscountEsher, Reginald Baliol Brett (2nd viscount) | Monograph or Collective Volume | Ivor Nicholson | 1938 |
| Justice Oliver Wendell Holmes and his days at Doneraile | Neely, Alfred S. | Article in Journal | | 1998 |
| Killeavy churches | Davies, Oliver | Article in Journal | | 1940 |
| Killeevan Abbey, Co. Monaghan | Davies, Oliver | Article in Journal | | 1940 |
| Killinagh church and Crom Cruaich | Davies, Oliver | Article in Journal | | 1939 |
| Killinagh Church and Crom Cruaich | Davies, Oliver | Article in Journal | | 2013 |
| Killinure: microcosm of the management of the Fitzwilliam estate: 1800-1864 | Whelan, Oliver | Article in Journal | | 2019 |
| Kilrane | Doyle, Oliver | Article in Journal | | 1998 |
| Knockcreghery | Doyle, Oliver | Article in Journal | | 1999 |
| Knocknacloy church | Davies, Oliver | Article in Journal | | 1940 |
| Knockroghery | Doyle, Oliver | Article in Journal | | 2000 |
| La vie et les lettres d'Olivier Goldsmith | Des Guerrois, Charles | Monograph or Collective Volume | | 1920 |
| Landholding in the new English settlement of Hacketstown, Co. Carlow, 1635-1875 | Whelan, Oliver | Monograph or Collective Volume | Four Courts Press | 2019 |
| Large prehistoric enclosures in Ireland | Davies, OliverMogey, J. M. | Article in Journal | | 1946 |
| Leacht Oliver-Brown | Rynne, Etienne | Article in Journal | | 1995 |
| Leo Broe, sculptor | MacMahon, Bryan, 1949- | Article in Journal | | 2022 |
| Letters to his son W.B. Yeats and others, 1869-1922 | | Monograph or Collective Volume | Faber | 1944 |
| Life in Dunshaughlin workhouse | Coogan, Oliver | Article in Journal | | 1982 |
| Life of Blessed Oliver Plunkett, archbishop of Armagh (1625-1681) | Stokes, John F. B. | Monograph or Collective Volume | Catholic Truth Society | 1954 |
| Limerick signalling 1910-2017 | Doyle, Oliver | Article in Journal | | 2017 |
| Lines of descent: genealogical imagination and creativity: the Carew and Lumley monuments | Harris, Oliver | Article in Book | | 2023 |
| Living proof | Lawlor, Stephen | Article in Journal | | 2014 |
| Looking for ancient woodland in Ireland | Rackham, Oliver | Article in Book | | 1995 |
| Lord Broghill and the Cromwellian union with Ireland and Scotland | Little, Patrick, 1969- | Monograph or Collective Volume | Boydell | 2004 |
| Love letters to a lady : Letters to Lady Castletown from Justice Oliver Wendell Homes, 1896-1926 | Power, Ita | Article in Journal | | 1993 |
| Made significant contribution to Irish historical writing | Anonymous | Article in Journal | | 2002 |
| Major General Oliver Harty in Brittany 1799-1800 | Van Brock, F. W. | Article in Journal | | 1981 |
| Major-General Oliver Nugent and the Ulster Division 1915-1918 | Nugent, Oliver Stewart Wood, Sir, d. 1926Perry, Nicholas | Monograph or Collective Volume | Sutton Publishing for the Army Records Society | 2007 |
| Malahide | Doyle, Oliver | Article in Journal | | 2000 |
| Malahide - 2 | Doyle, Oliver | Article in Journal | | 2000 |
| Malahide-Drogheda signalling | Doyle, Oliver | Article in Journal | | 1993 |
| Maria Edgeworth : the novelist and the Union | Topliss, I. | Article in Book | | 1986 |
| Martyrdom | Tait, Clodagh | Article in Book | | 2023 |
| Mayo line modernisation | Doyle, Oliver | Article in Journal | | 2007 |
| Meath : towards a history | Conway, Margaret | Monograph or Collective Volume | History Press Ireland | 2010 |
| Medieval town walls : an archaeology and social history of urban defence | Creighton, Oliver HamiltonHigham, Robert | Monograph or Collective Volume | Tempus | 2005 |
| Memoir of the Most Rev. Oliver Plunket, archbishop of Armagh, and Primate of all Ireland, who suffered death for the Catholic faith in the year 1681 | | Monograph or Collective Volume | | 1861 |
| Memoir of the Most Rev. Oliver Plunkett, archbishop of Armagh | Plunkett, Oliver, bishop and saint, 1625-1681
| Monograph or Collective Volume | [s.n.] | 1895 |
| Memory and commemoration of the Great Irish Famine | Gray, Peter, 1965- | Article in Book | | 2004 |
| Military maps : the one-inch series of Great Britain and Ireland | Hellyer, RogerOliver, Richard R. | Monograph or Collective Volume | Charles Close Society for the Study of Ordnance Survey Maps | 2004 |
| Military operations in county Louth in the run-up to Cromwell's storming of Drogheda | O'Sullivan, Harold | Article in Journal | | 1990 |
| Milltown - where Cromwell laid waste | Meagher, Jim | Article in Journal | | 1986 |
| Minutes of the proceedings of the Guardians of the Drogheda Union : July 1839 to March 1843 | Anonymous | Monograph or Collective Volume | St. Oliver's Community College | 1995 |
| Mixed marriages in pre-independence Ireland | Rafferty, Oliver P. | Article in Book | | 2019 |
| Modernisation of Iarnrod Eireann 1997-2010 | Doyle, Oliver | Article in Journal | | 2012 |
| Modernisation of Iarnród Éireann. 1997-2010 | Doyle, Oliver | Article in Journal | | 2012 |
| Moiry castle | Davies, Oliver | Article in Journal | | 1940 |
| Mountcastle | Davies, Oliver | Article in Journal | | 1938 |
| Moville abbey | Davies, Oliver | Article in Journal | | 1945 |
| Much ado about Oliver : the parliamentary dispute over Cromwell's statue | Battick, John F.Klimavicz, N. C. | Article in Journal | | 1974 |
| Murder as a metaphor : Griffin's portrayal of Ireland in the year of Catholic emancipation | Dunne, Tom, 1939- | Article in Book | | 1986 |
| Muslim immigration to thr Republic of Ireland: Trajectories and dynamics since World War II | Scharbrodt, Oliver | Article in Journal | | 2012 |
| National aid 1916-1917-1918 | Snoddy, Oliver | Article in Journal | | 1968 |
| Nationalist and Unionist ideology in the sculpture of Oliver Sheppard and John Hughes, 1895-1939 | Turpin, John | Article in Journal | | 1997 |
| New light on the family of Blessed Oliver Plunkett | Moran, Anne | Article in Journal | | 1959 |
| Newcastle West's link with 1916 | Snoddy, Oliver | Article in Journal | | 1966 |
| Nicholas Wiseman, ecclesiastical politics and Anglo-Irish relations in the mid nineteenth century | Rafferty, Oliver P. | Article in Journal | | 1993 |
| Nicholas Wiseman, ecclesiastical politics and Anglo-Irish relations in the mid-nineteenth century | Rafferty, Oliver P. | Article in Journal | | 1993 |
| Norman graveslabs from Co. Down | Davies, OliverGeorge, A. H.Others | Article in Journal | | 1947 |
| Norman Ireland in 1212 | Richardson, Henry Gerald | Article in Journal | | 1942 |
| Northern Catholics and the early years of the Troubles | Rafferty, Oliver P. | Article in Book | | 2013 |
| Not every judge a phoenix: King's Inns under Cromwell | Kenny. Colum | Article in Book | | 2020 |
| Notaí ar Chromail i mbéaloideas na h-Éireann | Ó hÓgáin, Dáithí | Article in Journal | | 1980 |
| Notes and documents. Account of money spent in the Cromwellian reconquest and settlement of Ireland, 1649-1656 | Firth, C. H. | Article in Journal | | 1899 |
| Notes on the Volunteers, militia, Orangemen and yeomanry of County Roscommon | Snoddy, Oliver | Article in Journal | | 1975 |
| Notes on the Volunteers, militia, yeomanry and Orangemen of County Cavan | Snoddy, Oliver | Article in Journal | | 1968 |
| Notes on the Volunteers, militia, yeomanry and Orangemen of County Waterford | Snoddy, Oliver | Article in Journal | | 1975 |
| Notes on the Volunteers, militia, yeomanry, and Orangemen of Co. Meath | Snoddy, Oliver | Article in Journal | | 1978 |
| Notes on the Volunteers, militia, yeomanry, Orangemen and fencibles in County Limerick | Snoddy, Oliver | Article in Journal | | 1971 |
| Notes on Volunteers, militia, yeomen and Orangemen of Co. Donegal | Snoddy, Oliver | Article in Journal | | 1969 |
| Notes. 'We have met the enemy, and they are ours': Oliver Hazard Perry and the Battle of Lake Erie | Kirby, Michael | Article in Journal | | 2013 |
| O'Connell : the life of Daniel O'Connell, 1775-1847 | MacDonagh, Oliver | Monograph or Collective Volume | | 1991 |
| O'Connell and Parnell | MacDonagh, Oliver | Monograph or Collective Volume | Magdalene College | 1994 |
| O'Connell and Parnell | MacDonagh, Oliver | Article in Book | | 1996 |
| O'Connell and repeal 1840-1845 | MacDonagh, Oliver | Article in Book | | 1983 |
| O'Connell in the House of Commons | MacDonagh, Oliver | Article in Book | | 1980 |
| O'Connell's ideology | MacDonagh, Oliver | Article in Book | | 1997 |
| O'Neill family history, 1721-2018 | O'Neill, William Oliver | Monograph or Collective Volume | The Author | 2019 |
| Obituary. Oliver Usher | Cummins, Kieran | Article in Journal | | 2023 |
| Obituary. Robert Oliver Cunningham | Anonymous | Article in Journal | | 1918 |
| Oilibhéar Pluincéid | Ó Fiaich, Tomás | Monograph or Collective Volume | Foilseacháin Ábhair Spioradálta | 1976 |
| Old chruches in the parish of Rossinver, county Leitrim | Davies, Oliver | Article in Journal | | 2013 |
| Old churches in county Louth : Drogheda barony | Davies, Oliver | Article in Journal | | 1947 |
| Old churches in the parish of Rossinver, Co. Leitrim | Davies, Oliver | Article in Journal | | 1946 |
| Old Ironsides : the military biography of Oliver Cromwell | Kitson, Frank | Monograph or Collective Volume | Weidenfeld and Nicolson | 2004 |
| Olibhéar Naomhtha Pluincéid | Ó Ciarghusa, S. | Article in Journal | | 1939 |
| Oliver : the story of the martyred archbishop of Armagh written for boys and girls | Gaffney, H. M. | Monograph or Collective Volume | Gill | 1946 |
| Oliver Bond | Maher, Maura | Article in Journal | | 1950 |
| Oliver Cromwell | Davis, J. C. (James Colin) | Monograph or Collective Volume | Arnold | 2001 |
| Oliver Cromwell | Gaunt, Peter | Monograph or Collective Volume | British Library | 2004 |
| Oliver Cromwell : an illustrated history | Litton, Helen | Monograph or Collective Volume | Wolfhound Press | 2000 |
| Oliver Cromwell : commander in chief | Hutton, Ronald | Monograph or Collective Volume | Yale University Press | 2024 |
| Oliver Cromwell : zur Geschichte eines schliesslichen Helden | Metz, Karl Heinz | Monograph or Collective Volume | Muster-Schmidt | 1993 |
| Oliver Cromwell and his times | Young, Peter, 1915-1988 | Monograph or Collective Volume | | 1962 |
| Oliver Cromwell and the 'Cromwellian' settlement of Ireland | Cunningham, John, 1984- | Article in Journal | | 2010 |
| Oliver Cromwell and the English revolution | NA | Monograph or Collective Volume | NA | 1990 |
| Oliver Cromwell and the siege of Clonmel | Ó Siochrú, Micheál | Article in Journal | | 2016 |
| Oliver Cromwell in Ireland | Synott, P. N. N. | Article in Journal | | 1974 |
| Oliver Cromwell in Ireland | Butler, William, Sir | Article in Book | | 1903 |
| Oliver Cromwell's latter end. An account of his last illness, death, burial and state funeral, the exhumation ordered by both Houses of Parliament, the state pageant, and an appendix on the death and burial of Henry Ireton, Lord Deputy of Ireland | Varley, F. J. | Monograph or Collective Volume | | 1939 |
| Oliver Cromwell's Policy toward the English Catholics : The Appraisal by Diplomats, 1654-1658 | Loomie, Albert Joseph | Article in Journal | | 2004 |
| Oliver Cromwell, 1658-1958. | Hill, Christopher, 1912-2003 | Monograph or Collective Volume | | 1984 |
| Oliver Cromwell, priestcraft, and the 'deluded and seduced' people of Ireland | Morrill, John | Article in Book | | 2019 |
| Oliver Cromwell, soldier : the military life of a revolutionary at war | Marshall, Alan | Monograph or Collective Volume | Brassey's | 2004 |
| Oliver Cromwell: father of Irish republicanism | Whelan, Fergus | Article in Journal | | 2010 |
| Oliver Cromwells Irlandpolitik | Berbig, H. J. | Article in Journal | | 1984 |
| Oliver Davies' field reports on archaeological sites in Clanmahon barony, county Cavan | Davies, Oliver | Article in Journal | | 2013 |
| Oliver Goldsmith | Lee, Gerard A. | Article in Journal | | 1972 |
| Oliver Goldsmith | Wardle, R. M. | Monograph or Collective Volume | Constable | 1958 |
| Oliver Goldsmith | Freeman, William | Monograph or Collective Volume | Longmans | 1952 |
| Oliver Goldsmith : essays towards an interpretation | Jackson, Robert Wyse | Monograph or Collective Volume | A.P.C.K. | 1951 |
| Oliver Goldsmith : his life and works | Sells, A. L. | Monograph or Collective Volume | | 1974 |
| Oliver Goldsmith and popular song | Shields, Hugh, 1929-2008 | Article in Journal | | 1983 |
| Oliver Goldsmith on Ireland and the Irish : personal views, shifting attitudes, literary stereotypes | Zach, Wolfgang | Article in Book | | 1982 |
| Oliver Goldsmith's Deserted Village (1770) and retrospective localism | McCormack, W. J. | Article in Book | | 2010 |
| Oliver Hill in Killiney : a Irish Victorian house remodelled | Lincoln, Simon | Article in Journal | | 1996 |
| Oliver Kelly, Archbishop of Tuam, 1815-1834 | Claffey, Anthony J. | Article in Book | | 2006 |
| Oliver Martyn and the Tribes of Galway | Martyn, G. V. | Article in Journal | | 1922 |
| Oliver Nugent and the Ulster Division on 1 July 1916 | Perry, Nicholas | Article in Journal | | 2017 |
| Oliver Nugent, the gentry and the Great War | Perry, Nicholas | Article in Book | | 2014 |
| Oliver Ormond Gerard MacDonagh 1924-2002 | Bull, Philip | Article in Journal | | 2002 |
| Oliver Plunket and the Popish Plot | Brady, John, d.1963 | Article in Journal | | 1958 |
| Oliver Plunkett, 1 : Ireland's new saint | Ó Fiaich, Tomás | Monograph or Collective Volume | Veritas | 1975 |
| Oliver Plunkett, 2 : In his own words | Forristal, Desmond | Monograph or Collective Volume | Veritas | 1975 |
| Oliver Plunkett, Francis Mac Donnell, O.F.M., and the mission to the Hebrides | Giblin, Cathaldus | Article in Journal | | 1975 |
| Oliver Plunkett, part I : Ireland's new saint; part II : in his own words | Forristal, DesmondÓ Fiaich, Tomás | Monograph or Collective Volume | Our Sunday Visitor by arrangement with Veritas Publications (Dublin) | 1975 |
| Oliver Pollock : forgotten financier of the American revolution | Roberts, Russell | Article in Journal | | 2005 |
| Oliver Pollock : the life and times of an unknown patriot | James, James Alton, 1864-1962 | Monograph or Collective Volume | Appleton | 1937 |
| Oliver Sheppard (1865-1941) : symbolist sculptor of the Irish cultural revival | Turpin, John | Monograph or Collective Volume | Four Courts | 2000 |
| Oliver Sheppard's 1798 memorials | Turpin, John | Article in Journal | | 1990 |
| Oliver Sheppard, Albert Power and state sculptural commissions | Turpin, John | Article in Journal | | 2002 |
| Oliver St John first manorial lord of Ballymore and Kernan | Anonymous | Article in Journal | | 2004 |
| Oliver St John Gogarty : a poet and his times | O'Connor, Ulick | Monograph or Collective Volume | Cape | 1964 |
| Oliver St John Gogarty : the man of many talents : a biography | Lyons, J. B. (John Benignus) | Monograph or Collective Volume | [s.n.] | 1980 |
| Oliver St John Gogarty, MD (1878-1957) : quintessential Irish Literary Renaissance figure | Carter, R. | Article in Journal | | 2006 |
| Oliver Ward R.I.P. | Corbally, John | Article in Journal | | 2018 |
| One of Blessed Oliver's lieutenants | Murray, L. P. | Article in Book | | 1937 |
| One of the great figures of British history : Oliver Cromwell | Coward, Barry | Article in Journal | | 1996 |
| Ormond and Cromwell: The Struggle for Ireland | Wheeler, James Scott | Article in Book | | 2021 |
| O’Connell and Parnell | MacDonagh, Oliver | Article in Book | | 2021 |
| Parliaments and politics during the Cromwellian protectorate | Little, Patrick, 1969-Smith, David L. (David Lawrence), 1963- | Monograph or Collective Volume | Cambridge University Press | 2007 |
| Patrick Pearse: a search for ideological parallels | Dennehy, Thomas Oliver | Thesis | | 1983 |
| Pluche and Derham, new sources of Goldsmith | Lynskey, Winifred | Article in Journal | | 1942 |
| Poetry and the avoidance of nationalism | Buckley, Vincent | Article in Book | | 1983 |
| Politics and war in Meath 1913-23 | Coogan, Oliver | Monograph or Collective Volume | Self Published | 1983 |
| Politics, 1830-1845 | MacDonagh, Oliver | Article in Book | | 1989 |
| Popular recreation in nineteenth-century Ireland | Malcolm, E. | Article in Book | | 1983 |
| Population change at Croghan, 1841-1911 | Dunne, Oliver | Article in Journal | | 2004 |
| Portraits of Blessed Oliver | Plunkett, George Noble, Count Plunkett | Article in Book | | 1937 |
| Portraits of Irish patriots by Oliver Sheppard, 1865-1941 | Turpin, John | Article in Journal | | 1996 |
| Potatoes and the sea | Oliver, Sandra L. | Article in Journal | | 1992 |
| Power, wealth and Catholic identity in Ireland, 1850-1900 | O'Neill, Ciaran | Article in Book | | 2013 |
| Poyntzpass | Doyle, Oliver | Article in Journal | | 1997 |
| Prelude to the Great Famine | MacDonagh, Oliver | Article in Book | | 1996 |
| Preparations for Oliver Cromwell's Irish campaign, February - July 1649 | De Grae, Emily | Article in Journal | | 2002 |
| Presentation Convent Rahan, Tullamore : a celebration of 175 years of service | | Monograph or Collective Volume | Esker Press for Offaly Historical and Archaeological Society | 1995 |
| Presentation Sisters Durrow : a record of 84 years | Byrne, Oliver | Monograph or Collective Volume | Presentation Sisters | 1998 |
| Press coverage from abroad | O'Hanlon, Oliver | Article in Book | | 2017 |
| Primary education as a political issue in O'Connell's time | Coolahan, John | Article in Book | | 1991 |
| Problems common to both protestant and catholic churches in eighteenth-century Ireland | Johnston, E. M. | Article in Book | | 1983 |
| Propaganda, rumour and myth : Oliver Cromwell and the massacre at Drogheda | Ó Siochrú, Micheál | Article in Book | | 2007 |
| Protestant interests? The 1641 rebellion and state formation in early modern Ireland | Gibney, John | Article in Journal | | 2011 |
| Purgatory re-visited : the historical context of Ó Bruadair | Irwin, Liam | Article in Book | | 2001 |
| Quadrupling Inchicore - Hazelhatch | Doyle, Oliver | Article in Journal | | 2011 |
| Quain's 'Elements of anatomy' | O'Rahilly, Ronan | Article in Book | | 1952 |
| Rahan looks back | Wrafter, Sister Oliver | Monograph or Collective Volume | The author | 1989 |
| Railways in Ireland 1834-1984 | Doyle, OliverHirsch, Stephen | Monograph or Collective Volume | Signal | 1983 |
| Rebels and informers : stirrings of Irish independence | Knox, Oliver | Monograph or Collective Volume | John Murray | 1997 |
| Recollections on Elphin and the Goldsmith connection | Rushe, Desmond | Article in Journal | | 1994 |
| Reflections on Oliver Goldsmith and politics - then and now | O'Ferrall, Fergus | Article in Journal | | 2011 |
| Representations of rebellion : 1798 in literature | Dunne, Tom, 1939- | Article in Book | | 1990 |
| Review article: 'Irish Protestant Identities', edited by Mervyn Busteed, Frank Neal and Jonathan Tonge, Manchester: University Press, 2008, pp.389 | Rafferty, Oliver P. | Article in Journal | | 2009 |
| Richard Talbot - the man who didn't kill Cromwell | Lenihan, Pádraig | Article in Journal | | 2015 |
| River Shannon bridge, Sligo line | Doyle, OliverMcAdam, Aidan | Article in Journal | | 2010 |
| River Shannon bridge, Sligo line | Doyle, Oliver | Article in Journal | | 2010 |
| Robert Phayre, the Kilshannig regicide. Parts 1- 2 | Twomey, Dermot | Article in Journal | | 2011 |
| Roger Casement's contribution to the ethnographical and economic botany collections in the National Museum of Ireland | Scannell, Mary J. P.Snoddy, Oliver | Article in Journal | | 1968 |
| Romewards | McManus, M. J. | Article in Book | | 1937 |
| Rosslare Harbour | Doyle, Oliver | Article in Journal | | 1967 |
| Rosslare line re-signalling | Doyle, Oliver | Article in Journal | | 2008 |
| Royalists, rebels and revolutionists: a history of County Cavan's revolution, 1912 - 1923 | Farrelly, Johann | Monograph or Collective Volume | Cavan County Council's Library Service | 2019 |
| Rural society in post-Cromwellian Ireland | Mac Curtain, Margaret | Article in Book | | 1979 |
| Saint Oliver of Armagh : the life of St Oliver Plunkett | Ó Fiaich, Tomás | Monograph or Collective Volume | Veritas | 1981 |
| Saint Oliver Plunkett | Meagher, John | Monograph or Collective Volume | Irish Messenger Publications | 1977 |
| Saint Oliver Plunkett 1625-1681 | Hanly, John J. | Article in Book | | 2001 |
| Saint Oliver Plunkett : journey to sainthood | Burns, Tommy | Monograph or Collective Volume | The author | 2014 |
| Saint Oliver Plunkett and Downside | Murphy, Martin | Monograph or Collective Volume | Downside Abbey | 1975 |
| Saint Oliver Plunkett and the diocese of Raphoe | Ó Fiaich, Tomás | Article in Journal | | 1975 |
| Samuel Rea 1725 - 1811 : heritage and descendants | Rea, Henry Oliver | Monograph or Collective Volume | Tyrone Printing Co. | 1960 |
| Seán O'Casey : the man behind the plays | Cowasjee, Saros | Monograph or Collective Volume | Oliver & Boyd | 1963 |
| Sean O'Casey as troublemaker | Snoddy, Oliver | Article in Journal | | 1966 |
| Seanchas na Midhe : a selection of lectures | Uí Chonmhidhe, Maighréad | Monograph or Collective Volume | Foilsítheoirí an Mhóta | 2009 |
| Sectarianism in Meath, 1792-98 | Coogan, Oliver | Article in Journal | | 1999 |
| Secular players : Catholic imagination, modern Irish writing and the case of John McGahern | Shovlin, Frank | Article in Book | | 2013 |
| Seigneurial and elite sites in the Medieval landscape | Barry, Terence B.Creighton, Oliver | Article in Book | | 2012 |
| Sessiaghmagaroll fort | Davies, OliverPaterson, T. G. F. | Article in Journal | | 1938 |
| Seventh report of the Royal Commission on Historical Manuscripts, with appendix and index . 2 pts. [C. 2340; C. 2340-i] | Royal Commission on Historical Manuscripts | Monograph or Collective Volume | | 1879 |
| Siege Massacres in Ireland, Drogheda in context | Lenihan, Pádraig | Article in Book | | 2021 |
| Sir Anthony MacDonnell and Crime Branch Special | Mandle, W. F. | Article in Book | | 1986 |
| Sir Antony MacDonnell and Crime Branch Special | Mandle, W. F. | Article in Book | | 1986 |
| Sir William Wilde and the teaching of oto-laryngology in Dublin | Wilson, T. G. | Article in Book | | 1952 |
| Slate pendant from Tirkane, Co. Londonderry | Davies, Oliver | Article in Journal | | 1946 |
| Sligo line mini-ctc & platforms | Doyle, Oliver | Article in Journal | | 2006 |
| Some aspects of Manx and (northern) Irish monument names | Muhr, Kay | Article in Book | | 2008 |
| Some time | Hopkin, Alannah | Article in Journal | | 2011 |
| Some Ulster Scots and their origins in Scotland | Oliver, John | Article in Journal | | 1987 |
| South Wexford line | Doyle, Oliver | Article in Journal | | 2011 |
| Speeches of Oliver Cromwell | | Monograph or Collective Volume | | 1989 |
| St Oliver Plunkett, Francis Macdonnell, O.F.M., and the mission to the Hebrides | Giblin, Cathaldus | Article in Journal | | 1974 |
| St. Oliver Plunkett : Deo Gratias | Burns, Thomas | Monograph or Collective Volume | Tommy Burns | 2000 |
| Stair fhir-cheart ar Éirinn | | Monograph or Collective Volume | | 1941 |
| States of mind : a study of Anglo-Irish conflict 1780-1980 | MacDonagh, Oliver | Monograph or Collective Volume | Allen & Unwin | 1983 |
| States of Mind : a study of Anglo-Irish conflict 1780-1980 | MacDonagh, Oliver | Monograph or Collective Volume | | 1983 |
| Stokes's optics I : Waves in lumeniferous ether | Darrigol, Oliver | Article in Book | | 2019 |
| Stokes's optics II : Other phenomena in light | Darrigol, Oliver | Article in Book | | 2019 |
| Surveys of Ireland in the seventeenth century | McLaughlin, P. J. | Article in Journal | | 1950 |
| Telling it slant : Swift and the journal to Stella | Steele, P. | Article in Book | | 1986 |
| The 'absenting of the bishop of Armagh' : eucharistic controversy and the English origins of Irish Catholic identity, 1550-51 | Murray, James | Article in Book | | 2013 |
| The 'greening' of Cardinal Manning | Casey, Fergal | Article in Book | | 2013 |
| The 1921 Millstreet ambush | Doyle, Oliver | Article in Journal | | 2011 |
| The age of O'Connell, 1830-1845 | MacDonagh, Oliver | Article in Book | | 1989 |
| The alternatives to civil war | Oliver, Frederick Scott, 1864-1934 | Monograph or Collective Volume | John Murray | 1913 |
| The ancestry of St. Oliver Plunket : a genealogical puzzle | Barnwell, S. B. | Article in Journal | | 1977 |
| The Anglo-Irish and the historians, 1830-1980 | Bolton, G. C. (Geoffrey Curgenven) | Article in Book | | 1983 |
| The appointment of blessed Oliver Plunket to Armagh | Ó Fiaich, Tomás | Article in Journal | | 1958 |
| The arrest of Oliver Plunkett | Brady, John, d.1963 | Article in Journal | | 1954 |
| The attitude of the Irish Catholic clergy towards emigration during the great famine | MacDonagh, Oliver | Article in Journal | | 1947 |
| The Australasian Response to the Irish Crisis, 1879-80 | Geary, Laurence M. | Article in Book | | 1989 |
| The autobiography of Oliver Goldsmith | | Monograph or Collective Volume | Ryerson press | 1943 |
| The background to the 1798 rebellion in County Meath | Kerrane, Joseph Gerard Oliver | Thesis | | 1971 |
| The battle of Collooney : some footnotes | Snoddy, Oliver | Article in Journal | | 1965 |
| The Boyne viaduct - heritage award | Doyle, Oliver | Article in Journal | | 2017 |
| The British Government and the appointment of Tomás Ó Fiaich as Archbishop of Armagh | Rafferty, Oliver P. | Article in Journal | | 2014 |
| The business of Dublin in the early 20th century: an overview of the retail and financial sector | Oliver, Emmet | Article in Journal | | 2018 |
| The cairn in Castle Archdale deer-park, Kiltierney, Fermanagh | Davies, Oliver | Article in Journal | | 1946 |
| The castle of Benburb | Davies, Oliver | Article in Journal | | 1941 |
| The castles of Co. Cavan | Davies, Oliver | Article in Journal | | 1948 |
| The castles of county Cavan | Davies, Oliver | Article in Journal | | 1948 |
| The Castles of county Cavan Part I|Part II | Davies, Oliver | Article in Journal | | 2013 |
| The castles of Innishowen | Davies, OliverSwan, H. P. | Article in Journal | | 1939 |
| The Catholic bishops and revolutionary violence in Ireland. Some 19th and 20th century comparisons | Rafferty, Oliver P. | Article in Journal | | 1994 |
| The Catholic chapel and the Catholic community : observance and tradition in nineteenth-cnetury County Down | Rafferty, Oliver P. | Article in Book | | 1997 |
| The Catholic Church and partition 1918-22 | Rafferty, Oliver P. | Article in Journal | | 1997 |
| The Catholic Church and the Nationalist community in Northern Ireland since 1960 | Rafferty, Oliver P. | Article in Journal | | 2008 |
| The Catholic Church and the Protestant state : nineteenth-century Irish realities | Rafferty, Oliver P. | Monograph or Collective Volume | Four Courts | 2008 |
| The Catholic Church in England in the nineteenth century : the Irish dimension | Rafferty, Oliver P. | Article in Book | Institute for Theological Partnerships Publishing | 2015 |
| The Catholic Church, Ireland and the British Empire, 1800-1921 | Rafferty, Oliver P. | Article in Journal | | 2011 |
| The Catholic Community in the Seventeenth and Eighteenth Centuries | Corish, Patrick J. | Monograph or Collective Volume | Ulster Historical Foundation | 2021 |
| The charter of the guild of St Luke, 1670 | Snoddy, Oliver | Article in Journal | | 1968 |
| The Cheney letters, 1682-85 | Dudley, Rowena | Article in Journal | | 1996 |
| The choosing of Oliver Kelly for the See of Tuam, 1809-15 | Coen, Martin | Article in Journal | | 1978 |
| The Christ of Maghera : a preliminary study of the lintel of the old church of St Lurach at Maghera, County Derry | Crilly, Oliver | Article in Book | | 2000 |
| The Church and the Easter Rising | Rafferty, Oliver P. | Article in Journal | | 2016 |
| The church, the state and the Fenian threat, 1861-75 | Rafferty, Oliver P. | Monograph or Collective Volume | Macmillan | 1999 |
| The Church, the State and the Fenian threat, 1861-75 | Rafferty, Oliver P. | Thesis | | |
| The churches of Armagh | Davies, OliverPaterson, T. G. F. | Article in Journal | | 1940 |
| The churches of county Cavan | Davies, Oliver | Article in Journal | | 1948 |
| The Churches of county Cavan | Davies, Oliver | Article in Journal | | 2013 |
| The Churches of county Cavan | Davies, OliverPaterson, T.G.F. | Article in Journal | | 2013 |
| The clergy of Blessed Oliver Plunkett | Mac Phóil, Donnchadha | Article in Journal | | 1959 |
| The clergy of Oliver Plunkett | Mac Phóil, Donnchadha | Article in Journal | | 1984 |
| The clergy of Oliver Plunkett | Mac Phóil, Donnchadha ; Campbell, P. J. | Article in Journal | | 1986 |
| The clergy of Oliver Plunkett [part 5] | Campbell, Patrick J.Mac Phóil, Donnchadha | Article in Journal | | 1986 |
| The Confederation of Kilkenny | O'Doherty, J. F. | Article in Book | | 1937 |
| The Connaught Rangers Association founded [2002] | Fallon, Oliver | Article in Journal | | 2002 |
| The contribution of O'Connell | MacDonagh, Oliver | Article in Book | | 1973 |
| The Craig collection in Armagh Museum | Davies, OliverPatterson, T. G. F. | Article in Journal | | 1940 |
| The Cromwellian assault on Clonmel | Lyons, Patrick, 1861-1954 | Article in Book | | 1950 |
| The Cromwellian conquest, 1649-53 | Corish, Patrick J. | Article in Book | | 1976 |
| The Cromwellian gazeteer : an illustrated guide to Britain in the civil war and commonwealth | Gaunt, Peter | Monograph or Collective Volume | Allan Sutton and the Cromwellian Association | 1987 |
| The Cromwellian gazetteer | Gaunt, Peter | Monograph or Collective Volume | Sutton | 2000 |
| The Cromwellian government and the transportation to Connacht | Herlihy, Kevin | Article in Journal | | 1993 |
| The Cromwellian persecution, and the Catholic Church in Ireland | Edwards, R. W. D. (Robert Walter Dudley) | Article in Book | | 1937 |
| The Cromwellian protectorate | Coward, Barry | Monograph or Collective Volume | Manchester University Press | 2002 |
| The Cromwellian regime | Corish, Patrick J. | Article in Book | | 1976 |
| The Cromwellian siege of Kilkenny | Keane, John E. Kerry | Article in Book | | 2009 |
| The Cromwellian Urban Surveys, 1653-1659 [with index | Brown, DavidÓ Siochrú, Micheál | Article in Journal | | 2016 |
| The curse of Cromwell | O Siochrú, Micheál | Article in Journal | | 2008 |
| The curse of Cromwell : a history of the Ironside conquest of Ireland, 1649-53 | Esson, Denis Main Ross | Monograph or Collective Volume | Leo Cooper | 1971 |
| The Curse of Cromwell : Warrington's Statue of Oliver Cromwell | Cunniffe, SteveWyke, Terry J. | Article in Journal | | 2009 |
| The curse of Cromwell : Warrington's statue of Oliver Cromwell | Cunniffe, Steve ; Wyke, Terry | Article in Journal | | 2009 |
| The curse of Cromwell. The story of the campaigh 1649-50 | de Blacam, Aodh | Article in Journal | | 1951 |
| The Death of Cuchulainn in the GPO | Kennedy, Róisín | Article in Book | | 2017 |
| The descendants of Oliver Fitzgerald of Belagh | Nicholls, K. W. (Kenneth W.) | Article in Journal | | 1968 |
| The desolate boys : juvenile crime and punishment, Ireland and New South Wales | Robinson, Portia | Article in Book | | 1986 |
| The desolute boys : juvenile crime and punishment, Ireland and New South Wales | Robinson, P. | Article in Book | | 1986 |
| The development of William Butler Yeats | Grierson, Herbert John Clifford, SirMenon, V. K. Narayana | Monograph or Collective Volume | Oliver & Boyd | 1942 |
| The devil from over the sea : remembering and forgetting Oliver Cromwell in Ireland | Covington, Sarah | Monograph or Collective Volume | Oxford University Press | 2022 |
| The devotional landscape of medieval Irish cultural Catholicism inter hibernicos et inter anglicos, c.1200 - c.1550 | Ryan, Salvador | Article in Book | | 2013 |
| The Drogheda massacre in Cromwellian context | Morrill, John Stephen, 1946- | Article in Book | | 2007 |
| The Dublin house of industry | Widdess, J. D. H. | Article in Book | | 1952 |
| The economy and society, 1830-1845 | MacDonagh, Oliver | Article in Book | Clarendon Press | 1989 |
| The Emancipist, Daniel O'Connell 1830-1847 | MacDonagh, Oliver | Monograph or Collective Volume | Weidenfeld and Nicolson | 1989 |
| The energy within : parish pastoral councils today - discern, decide, implement, involve | Doherty, Johnny ; Coyle, Paddi ; Crilly, Tony ; Crilly, Oliver | Monograph or Collective Volume | Veritas Publications | 2017 |
| The Englishman Who Cried ‘Let Ireland Go’ | O'Hanlon, Oliver | Article in Journal | | 2024 |
| The Esmonde family of Co. Wexfrod and Catholic loyalty | Keogh, RichardMcConnel, James | Article in Book | | 2013 |
| The evolution of constitutional policy in Northern Ireland over the past fifteen years | Oliver, John | Article in Book | | 1982 |
| The fall and return of John Macmoyer | Ó Fiaich, Tomás | Article in Journal | | 1958 |
| The Fetherston family of Ardagh | Hodgins, John | Article in Journal | | 1980 |
| The financial relations question, 1800-1914 | Travers, Pauric | Article in Book | | 1990 |
| The first and final phases of the Irish medical students at the university of Leyden | Underwood, Edgar Ashworth | Article in Book | | 1978 |
| The first French translation of 'The Deserted Village' | Remak, Henry H. H.Seeber, Edward D. | Article in Journal | | 1946 |
| The folkloric afterlife of Oliver Cromwell in Ireland | Covington, Sarah | Article in Book | NA | 2021 |
| The formation of Hiberno-Argentine | McKenna, Patrick | Article in Book | | 2000 |
| The foundation of Christianity in the parish of Kilkeevan (Castlerea) | Wall, Oliver | Article in Journal | | 1994 |
| The friendship of Justice Holmes and Canon Sheehan | Burton, David H. | Article in Journal | | 1977 |
| The Gaelic Athletic Association and popular culture, 1884-1924 | Mandle, W. F. | Article in Book | | 1983 |
| The Galway medical school | Shea, Stephen | Article in Book | | 1952 |
| The great Irish crosses : meaning and mystery | Crilly, Oliver | Monograph or Collective Volume | Columba | 2013 |
| The greatness of Oliver Cromwell | Ashley, Maurice Percy | Monograph or Collective Volume | Hodder and Stoughton | 1957 |
| The head of Saint Patrick at Armagh | Davies, OliverPatterson, T. G. F. | Article in Journal | | 1940 |
| The hereditary bondsman : Daniel O'Connell 1775-1829 | MacDonagh, Oliver | Monograph or Collective Volume | Weidenfeld and Nicolson | 1988 |
| The high crosses of Ireland : meaning and mystery | Crilly, Oliver | Monograph or Collective Volume | Columba Press | 2013 |
| The historiography of the Cromwellian siege of Drogheda, 1649 | Wheeler, James Scott | Article in Book | | 2023 |
| The history of the construction of Tuam Cathedral | Higgins, Patrick | Article in Journal | | 2010 |
| The images of nations in eighteenth-century satire | Knight, Charles A. | Article in Journal | | 1989 |
| The Inspector General : Sir Jeremiah Fitzpatrick and the politics of social reform, 1783-1802 | MacDonagh, Oliver | Monograph or Collective Volume | Croom Helm | 1981 |
| The Irish and Law in Australia | Brennan, G. | Article in Journal | | 1986 |
| The Irish and law in Australia | Brennan, Gerard | Article in Book | | 1986 |
| The Irish Catholic Church under Charles II : the ‘Popish Plot’ and the martyrdom of Oliver Plunkett | Considère-Charon, Marie-Claire | Article in Journal | | 2013 |
| The Irish Catholic clergy and emigration during the great famine | MacDonagh, Oliver | Article in Journal | | 1947 |
| The Irish Catholics and the Puritan revolution | Edwards, R. W. D. (Robert Walter Dudley) | Article in Book | | 1957 |
| The Irish famine emigration to the United States | MacDonagh, Oliver | Article in Journal | | 1976 |
| The Irish in Australia - a general view | MacDonagh, Oliver | Article in Book | | 1986 |
| The Irish in Victoria, 1851-91 : a demographic essay | MacDonagh, Oliver | Article in Journal | | 1971 |
| The Irish parliament of 1689 | Preston, Christopher | Article in Journal | | 1948 |
| The Irish Pipe Roll of 14 John, 1211-1212 | | Article in Journal | | 1941 |
| The Irish pipe roll of John, 1211-1212 | | Article in Journal | | 1941 |
| The Irish Republican Brotherhood in Australia : the 1918 internments | O'Farrell, Patrick James | Article in Book | | 1983 |
| The Irish revenues of Oliver St John, Viscount Grandison for 1625-9 | Mac Cuarta, Brian | Article in Journal | | 2014 |
| The Irish theatre | Fitz-Simon, Christopher | Monograph or Collective Volume | Thames & Hudson | 1983 |
| The kin of Blessed Oliver Plunkett | Brady, J. | Article in Journal | | 1945 |
| The King's Irishmen : the Irish in the exiled court of Charles II, 1649-1660 | Williams, Mark R. F. | Monograph or Collective Volume | Boydell | 2014 |
| The largest and most ornate cuckoo's egg ever laid in a songbird's nest. Belfast Municipal Technical Institute 1906-2006 | Dudman, Moyra | Article in Journal | | 2005 |
| The last bill of pains and penalties : the case of Daniel O'Sullivan, 1869 | MacDonagh, Oliver | Article in Journal | | 1974 |
| The last gasp of Southern unionism : Lord Ashtown of Woodlawn | Curtis, L. Perry, jr. | Article in Journal | | 2005 |
| The last lords of Ormond : the Cromwellian plantation in the 'countrie of the three O'Kennedys' | Gleeson, Dermot F.Grace, Daniel | Monograph or Collective Volume | Relay | 1997 |
| The last speech of Blessed Oliver Plunket | | Article in Journal | | 1947 |
| The leech in ancient Ireland | Binchy, D. A. (Daniel Anthony), 1900-1989 | Article in Book | | 1952 |
| The letters of Blessed Oliver | Concannon, Helena | Article in Book | | 1937 |
| The Letters of Oliver Goldsmith | Goldsmith, Oliver, 1728-1774 | Monograph or Collective Volume | Cambridge University Press | 2018 |
| The letters of Oliver Plunkett, 1625-81, archbishop of Armagh and primate of all Ireland | Hanly, JohnPlunkett, Oliver, bishop and saint, 1625-1681 | Monograph or Collective Volume | Dolmen Press | 1979 |
| The letters of Saint Oliver Plunkett, 1625-1681 : Archbishop of Armagh and Primate of all Ireland | | Monograph or Collective Volume | | 1979 |
| The letters of Saint Oliver Plunkett, 1625-1681, Archbishop of Armagh and Primate of All Ireland | | Monograph or Collective Volume | | 1979 |
| The letters of St. Oliver Plunkett | | Monograph or Collective Volume | Dolmen Press | 1979 |
| The Life of Oliver Goldsmith. With selections from his writings | Irving, Washington | Monograph or Collective Volume | | 1849 |
| The life of Oliver Sheppard, Dublin sculptor, 1865-1941. Parts 1-2 | Turpin, John | Article in Journal | | 1995 |
| The Limerick city militia and the battle of Collooney, 1798 | Snoddy, Oliver | Article in Journal | | 1964 |
| The Locke's tribunal, 1947 | Gibney, John | Article in Journal | | 2010 |
| The medical families of medieval Ireland | Dunlevy, Mairead | Article in Book | | 1952 |
| The midland volunteer force 1913 | Snoddy, Oliver | Article in Journal | | 1969 |
| The mystery of Oliver Goldsmith's medical degree | Lyons, J. B. (John Benignus) | Article in Journal | | 1962 |
| The New Model Army and the problems of siege warfare, 1648-1651 | Burke, James | Article in Journal | | 1990 |
| The new model army in England, Ireland and Scotland, 1645-1653 | Gentles, Ian | Monograph or Collective Volume | Blackwell Publishers | 1991 |
| The nineteenth century novel and Irish social history : some aspects | MacDonagh, Oliver | Monograph or Collective Volume | National University of Ireland | 1971 |
| The O'Rahilly | Snoddy, Oliver | Article in Journal | | 1967 |
| The Oliver Davies lecture : Regal ( and other) patronage in Irish inscriptions of the pre-Norman period | Harbison, Peter | Article in Journal | | 1999 |
| The Order of Liberators | Snoddy, Oliver | Article in Journal | | 1966 |
| The Ordnance Survey in the nineteenth century | Oliver, Richard | Monograph or Collective Volume | Charles Close Society | 2014 |
| The other Irish martyr of the Titus Oates Plot | Cronin, J. M. | Article in Book | | 1937 |
| The overflow of the deluge : Anglo-Irish relationships, 1914-1922 | Fitzpatrick, David | Article in Book | | 1986 |
| The past is prologue | Little, G. A. | Article in Book | | 1952 |
| The penal laws against Irish Catholics : were they too good for them? | Bartlett, Thomas | Article in Book | | 2013 |
| The persecuted primate | Ó Meachair, Liam S. | Article in Journal | | 1957 |
| The place of Oliver Plunket in history | Edwards, R. W. D. (Robert Walter Dudley) | Article in Book | | 1937 |
| The Plunket family | Walsh, Paul, Revd, 1885-1941 | Article in Book | | 1937 |
| The politicization of the Irish Catholic bishops, 1800-1850 | MacDonagh, Oliver | Article in Journal | | 1975 |
| The poor law, emigration and the Irish question, 1830-55 | MacDonagh, Oliver | Article in Journal | | 1958 |
| The Presentation foundation Drogheda 7th June, 1813 | Allen, M. Oliver | Article in Journal | | 1990 |
| The priest in politics : the case of conscription | Travers, Pauric | Article in Book | | 1983 |
| The priesthood of St Oliver | Ó Fiaich, Tomás | Article in Journal | | 1975 |
| The private estate of James II | Kingston, John | Article in Journal | | 1960 |
| The regulation of the emigrant traffic from the United Kingdom, 1842-55 | MacDonagh, Oliver | Article in Journal | | 1954 |
| The religious orders in Ireland in the seventeenth century | Jennings, Brendan | Article in Book | | 1937 |
| The riddle of Goldsmith's ancestry | Murray, Patrick | Article in Journal | | 1974 |
| The seventeenth century Reliquary of St Oliver Plunkett at the Siena Convent, Drogheda | Bellew, Séamus | Article in Journal | | 2011 |
| The Skerries Harps | Moore, OliverWalsh, Bobby | Article in Journal | | 2000 |
| The Social Memory of Oliver Cromwell in Ireland, c.1660s–c.1730s | Darcy, Eamon | Article in Book | | 2021 |
| The Stormont administration | Oliver, John | Article in Book | | 1991 |
| The Story of the British Isles in 100 places | Oliver, Neil | Monograph or Collective Volume | Bantam Press | 2018 |
| The strange enigma of Oliver Goldsmith | Welch, Robert | Article in Book | | 2001 |
| The struggle for new constitutional and institutional forms | Smith, David L. (David Lawrence), 1963- | Article in Book | | 1992 |
| The student Oliver | Curran, M. J. | Article in Book | | 1937 |
| The swordsmen in power : war and politics under the English republic, 1649-1660 | Hainsworth, D. Roger | Monograph or Collective Volume | Sutton | 1997 |
| The transplantation to Connacht, 1654-8 | Simington, Robert C. | Monograph or Collective Volume | | 1970 |
| The transplanters' certificates and the historiography of Cromwellian Ireland | Cunningham, John, 1984- | Article in Journal | | 2011 |
| The trial of Oliver Plunkett | Curtayne, Alice | Monograph or Collective Volume | Sheed & Ward | 1953 |
| The trial of Oliver Plunkett | Curtayne, Alice | Article in Journal | | 1954 |
| The trial of the primate | Curran, C. P. | Article in Book | | 1937 |
| The truce | Snoddy, Oliver | Article in Journal | | 1971 |
| The ultramontane spirituality of Paul Cullen | Rafferty, Oliver P. | Article in Book | | 2011 |
| The Victorian Bank, 1824-1914 | MacDonagh, Oliver | Article in Book | | 1983 |
| The voices of Catholic women in Ireland, 1800-1921 | Clear, Caitriona | Article in Book | | 2013 |
| The Volunteers of Ireland | Snoddy, Oliver | Article in Journal | | 1965 |
| The Volunteers, militia, yeomanry and Orangemen of Co. Kildare in the eighteenth century | Snoddy, Oliver | Article in Journal | | 1971 |
| The wild geese. Pen portraits of famous Irish exiles | Griffin, Gerald | Monograph or Collective Volume | | 1938 |
| The workhouse in Dunshaughlin | Coogan, Oliver | Article in Journal | | 1978 |
| The writings and speeches of Oliver Cromwell | Abbott, Wilbur CortezCrane, Catherine D.Cromwell, Oliver, 1599-1658Gleason, M. R. | Monograph or Collective Volume | | 1937 |
| The year of Oliver Goldsmith's birth | Friedman, Arthur | Article in Journal | | 1951 |
| The years of Blessed Oliver's primacy | D'Alton, J. F., Canon | Article in Book | | 1937 |
| Time's Revenges and Revenge's Time : a view of Anglo-Irish Relations | MacDonagh, Oliver | Article in Journal | | 1979 |
| Tipperary and the Titanic | Brennan, Oliver | Article in Journal | | 2003 |
| Transitus Beati Fursei : a translation of the 8th century manuscript life of Saint Fursey | Rackham, Oliver | Monograph or Collective Volume | Fursey Pilgrims | 2007 |
| Trees against the sky | Caffrey, Paul | Article in Journal | | 2018 |
| Tuam two centuries ago | Claffey, Tony | Article in Journal | | 2015 |
| Two issues of Goldsmith's 'Bee' | Knight, Douglas | Article in Journal | | 1944 |
| Two military medals by William Mossop (1751-1805) | Snoddy, Oliver | Article in Journal | | 1964 |
| Two unacknowledged adaptations from Goldsmith | Barnett, George E. | Article in Journal | | 1946 |
| Two unpublished letters of Oliver Cromwell | Jones, Clyve | Article in Journal | | 1973 |
| Types and distribution of Ulster churches | Davies, Oliver | Article in Journal | | 1941 |
| Types of rath in southern Ulster | Davies, Oliver | Article in Journal | | 2013 |
| Tyrrellspass : past and present | Egan, Oliver | Monograph or Collective Volume | Tyrrellspass Town Development Committee | 1986 |
| Uiriamu Aren : ferutobo seizoko, ajitita, airurand osiefuku = [Felt hat manufacturerer and agitator William Allen and the subjugation of Ireland] | Onishi, Haruki | Article in Journal | | 1995 |
| Under the hammer blow | Phelan, Mark | Article in Journal | | 2018 |
| University College Dublinh and Spanish fascism - an unlikely partnership? | Whelan, Barry | Article in Journal | | 2014 |
| Urn from Comber, Co. Down | Davies, Oliver | Article in Journal | | 1946 |
| Vale Oliver Mac Donagh | McClaughlin, TrevorMyton, David | Article in Journal | | 2004 |
| Valentia and the Knight of Kerry | Fitzgerald, A. | Article in Book | | 1991 |
| Verité et justice comme remèdes au trauma: 'Bloody Sunday' et l'enquête Saville | Barcat, Charlotte
| Article in Journal | | 2011 |
| Violence transported : aspects of Irish peasant society | Johnston, E. M. | Article in Book | | 1986 |
| Violence, politics and Catholicism in Ireland | Rafferty, Oliver P. | Monograph or Collective Volume | Four Courts | 2016 |
| War and politics in Ireland 1649-1730. | Hayton, D. W. (David William)O'Brien, GerardSimms, J. G. (John Gerald) | Monograph or Collective Volume | Hambledon | 1986 |
| War criminal allegations : The case for the defence | Reilly, Tom | Article in Book | NA | 2021 |
| Westland Row layout 1891 | Doyle, Oliver | Article in Journal | | 2004 |
| What federalism is not | Oliver, Frederick Scott, 1864-1934 | Monograph or Collective Volume | John Murray | 1914 |
| What was new in the New Ireland forum? | MacDonagh, Oliver | Article in Journal | | 1985 |
| What's in a name? | Oliver, J. D. B. | Article in Book | | 2004 |
| What's past is prologue : a retrospect of Irish medicine | | Monograph or Collective Volume | Monument Press | 1952 |
| When royalist Bandon switched to support of Cromwell | Bradley, Pamela | Article in Journal | | 1993 |
| White Island church door | Davies, Oliver | Article in Journal | | 1939 |
| Who succeeded Blessed Oliver Plunkett? | Ó Fiaich, Tomás | Article in Journal | | 1956 |
| Who will be Ireland's next canonised saint? : a study of Blessed Oliver Plunkett | Bastible, J. | Article in Journal | | 1939 |
| Why was Charles I executed? | Holmes, Clive | Monograph or Collective Volume | Hambledon | 2006 |
| Why was Oliver Plunket arrested? | Brady, John, d.1963 | Article in Journal | | 1955 |
| William Butler Yeats : a memoir | Dillon, MylesGogarty, Oliver St John | Monograph or Collective Volume | Dolmen Press | 1963 |
| William Harnett : master of eye-deceiving realism | Snoddy, Oliver | Article in Journal | | 1976 |
| William Joyce - Lord Haw Haw : from Galway to the Third Reich and back again | Curley, MarieCurley, Oliver | Article in Journal | | 1998 |
| William O'Brien : problems reappraising his political career | Bull, Philip | Article in Book | | 1986 |
| Working at Stormont : memoirs | Oliver, John | Monograph or Collective Volume | Institute of Public Administration | 1978 |
| Writing the history of Irish-Australia | O'Farrell, Patrick James | Article in Book | | 1986 |
| Writings 1947-89 | MacDonagh, Oliver | Article in Book | | 1990 |
| Yeats and the Anglo-Irish twilight | Lyons, F. S. L. (Francis Stewart Leland) | Article in Book | | 1983 |
| Young Ireland and French Romanticism | Oliver, Sean | Article in Book | | 1998 |
| ‘By far the greatest & most perpetual source of happiness in my life has been, & is, seeing’: Christopher Hussey’s visits to country houses, 1920–70 | Cox, Oliver | Article in Book | | 2023 |
| ‘Halt! Halt!’ Oliver Cromwell, Hugh O’Neill and the Siege of Clonmel, April–May 1650 | Marshall, Alan | Article in Book | | 2021 |
| ‘Sr Richard Burk of the Newtowne knight otherwise called MacWilliam Eighter’ | Keenan, Declan | Article in Book | | 2018 |
| ‘This day by letters severall from hands’ News Networks and Oliver Cromwell’s Letters from Drogheda | Poyntz, Nick | Article in Book | | 2021 |