| "A poor thing but our own" : The Joint Intelligence Committee and Ireland, 1965-72 | O'Halpin, Eunan | Article in Journal | | 2008 |
| "Hitler's Irish hideout" : a case study of SOE's black propaganda battles | O'Halpin, Eunan | Article in Book | Routledge | 2006 |
| "Toys" and "Whispers" in "16-Land" : SOE and Ireland, 1940-1942 | O'Halpin, Eunan | Article in Journal | | 2000 |
| "Weird prophecies" : British intelligence and Anglo-Irish relations, 1932-3 | O'Halpin, Eunan | Article in Book | Four Courts Press | 2000 |
| 'According to the Irish minister in Rome ...' : British decrypts and Irish diplomacy in the Second World War | O'Halpin, Eunan | Article in Journal | | 1995 |
| 'I am sure there was confidence in Nero' | O'Halpin, Eunan | Article in Book | | 2015 |
| A Greek authoritarian phase? the Irish army and the Irish crisis, 1969-70 | O'Halpin, Eunan | Article in Journal | | 2008 |
| Anglo-Irish security co-operation since 1969 : a Dublin perspective | O'Halpin, Eunan | Article in Journal | | 1990 |
| Army, politics and society in independent Ireland, 1923-1945 | O'Halpin, Eunan | Article in Book | | 1993 |
| Aspects of intelligence | O'Halpin, Eunan | Article in Journal | | 1993 |
| Augustine Birrell | O'Halpin, Eunan | Article in Book | Royal Irish Academy | 2015 |
| Britain's neutral neighbours : Ireland and Afghanistan compared, 1939-1945 | O'Halpin, Eunan | Article in Book | | 2007 |
| British intelligence in Ireland, 1914-1921 | O'Halpin, Eunan | Article in Book | | 1984 |
| British intelligence, the republican movement and the IRA's German links, 1935-45 | O'Halpin, Eunan | Article in Book | | 2003 |
| British patronage and an Irish writer : the background to the award of a government grant to James Joyce in 1916 | O'Halpin, Eunan | Article in Journal | | 1986 |
| Collins and intelligence 1919-1923 : from brotherhood to bureaucracy | O'Halpin, Eunan | Article in Book | | 1998 |
| Defending Ireland : the Irish state and its enemies since 1922 | O'Halpin, Eunan | Monograph or Collective Volume | Oxford University Press | 1999 |
| Documents on Irish foreign policy : vol. 4 : 1932-1936 | | Monograph or Collective Volume | Royal Irish Academy | 2004 |
| Documents on Irish foreign policy, vol. 1 : 1919-1922 | | Monograph or Collective Volume | Royal Irish Academy | 1998 |
| Documents on Irish foreign policy, vol. 10, 1951-1957 | NA | Monograph or Collective Volume | Royal Irish Academy | 2016 |
| Documents on Irish foreign policy, vol. 2 : 1923-1926 | | Monograph or Collective Volume | Royal Irish Academy | 2000 |
| Documents on Irish foreign policy, vol. 3 : 1926-1932 | | Monograph or Collective Volume | Royal Irish Academy | 2002 |
| Documents on Irish foreign policy, vol. 7 : 1941-1945 | | Monograph or Collective Volume | Royal Irish Academy | 2010 |
| Documents on Irish foreign policy, vol. 8, 1945-1948 | | Monograph or Collective Volume | Royal Irish Academy | 2013 |
| Documents on Irish foreign policy, vol. 9, 1948-1951 | | Monograph or Collective Volume | Royal Irish Academy | 2014 |
| Documents on Irish foreign policy, vol. XI, 1957-1961 | | Monograph or Collective Volume | Royal Irish Academy | 2018 |
| Documents on Irish foreign policy, vol. XII, 1961-1965 | NA | Monograph or Collective Volume | Royal Irish Academy | 2020 |
| Documents on Irish foreign policy, vol. XIII, 1965-1969 | NA | Monograph or Collective Volume | Royal Irish Academy | 2022 |
| Documents on Irish foreign policy, vol. XIV, 1969-1973 | NA | Monograph or Collective Volume | Royal Irish Academy | 2024 |
| Documents on Irish Foreign policy. vol. 5 : 1937-1939 | | Monograph or Collective Volume | Royal Irish Academy | 2006 |
| Documents on Irish foreign policy. vol. 6 : 1939-1941 | | Monograph or Collective Volume | Royal Irish Academy | 2008 |
| Epilogue : remembering and forgetting in modern Irish history | Beiner, GuyO'Halpin, Eunan | Article in Book | | 2016 |
| External Intelligence and the Civil War | O'Halpin, Eunan | Article in Journal | | 1997 |
| Female revolutionaries and political violence in India and Ireland, 1919-39 | O'Halpin, Eunan | Article in Book | | 2023 |
| Fianna Fáil on the highwire of foreign policy | O'Halpin, Eunan | Article in Book | | 1996 |
| Frank Sherwin : independent and unrepentent | O'Halpin, EunanSherwin, Frank, 1905-1981Sherwin, Frank, Jr. | Monograph or Collective Volume | Irish Academic Press | 2007 |
| H.E. Duke and the Irish administration, 1916-18 | O'Halpin, Eunan | Article in Journal | | 1981 |
| Historical revisit : Dorothy Macardle, The Irish Republic (1937) | O'Halpin, Eunan | Article in Journal | | 1999 |
| India, Ireland and anti-imperial struggle : remembering the Connaught Rangers mutiny, 1920 | | Monograph or Collective Volume | Aakar Books | 2021 |
| Intelligence and Anglo-Irish relations, 1922-73 | O'Halpin, Eunan | Article in Book | | 2006 |
| Intelligence and security in Ireland, 1922-45 | O'Halpin, Eunan | Article in Journal | | 1990 |
| Intelligence, statecraft and international power; papers read before the 27th Irish Conference of Historians held at Trinity College, Dublin 19-21 May 2005 : Historical Studies XXV | | Monograph or Collective Volume | Irish Academic Press | 2006 |
| Ireland in spy fiction | Jeffery, KeithO'Halpin, Eunan | Article in Journal | | 1991 |
| Ireland, 1854-1939 | O'Halpin, Eunan | Article in Book | | 1987 |
| Irish neutrality in the Second World War | O'Halpin, Eunan | Article in Book | | 2002 |
| Irish-Allied security relations and the "American note" crisis : new evidence from British records | O'Halpin, Eunan | Article in Journal | | 2000 |
| Labour and the making of Irish foreign policy, 1973-77 | O'Halpin, Eunan | Article in Book | | 2012 |
| Long fellow, long story : MI5 and de Valera | O'Halpin, Eunan | Article in Journal | | 2003 |
| MI5 and Ireland, 1939-1945 : the official history | | Monograph or Collective Volume | Irish Academic Press | 2003 |
| MI5's Irish memories : fresh light on the origins and rationale of Anglo-Irish security liaison in the Second World War | O'Halpin, Eunan | Article in Book | | 2000 |
| Northern Ireland : the troubled peace process | O'Halpin, Eunan | Article in Journal | | 2001 |
| Parliamentary party discipline and tactics : the Fianna Fáil archives, 1926-32 | O'Halpin, Eunan | Article in Journal | | 1997 |
| Policy making | O'Halpin, Eunan | Article in Book | | 1992 |
| Politics and the state, 1922-32 | O'Halpin, Eunan | Article in Book | | 2003 |
| Problematic killing during the War of Independence and its aftermath : civilian spies and informers | O'Halpin, Eunan | Article in Book | | 2013 |
| Registered 'unknown' infant fatalities in Ireland, 1916-32: gender and power | Breathnach, CiaraO'Halpin, Eunan | Article in Journal | | 2012 |
| Sources for Labour history : the Walter Long and Field Marshal Lord French papers | O'Halpin, Eunan | Article in Journal | | 1989 |
| Spying on Ireland : British intelligence and Irish neutrality during the Second World War | O'Halpin, Eunan | Monograph or Collective Volume | Oxford University Press | 2008 |
| The army and the Dáil - civil/military relations within the independence movement | O'Halpin, Eunan | Article in Book | | 1994 |
| The army in independent Ireland | O'Halpin, Eunan | Article in Book | | 1996 |
| The Connaught Rangers mutiny in its wider context : military discipline, loyalty and sedition and India, 1914-21 | O'Halpin, Eunan | Article in Book | | 2021 |
| The Dail committee of public accounts, 1961-1980 | O'Halpin, Eunan | Article in Journal | | 1985 |
| The Dead of the Irish Revolution | O'Halpin, EunanÓ Corráin, Daithí | Monograph or Collective Volume | Yale UP | 2020 |
| The decline of the Union : British government in Ireland 1892-1920 | O'Halpin, Eunan | Monograph or Collective Volume | Gill & Macmillan|Syracuse University Press | 1987 |
| The French legation in Dublin in comparative perspective, 1939-45 | Harrison, Alice,O'Halpin, Eunan, | Article in Book | | 2009 |
| The geopolitics of republican diplomacy in the twentieth century | O'Halpin, Eunan | Article in Book | | 2004 |
| The Irish 'nation' and the challenge of ethical commemoration | O'Halpin, Eunan | Article in Book | | 2023 |
| The Irish administration in crisis, 1916-1920 | O'Halpin, Eunan | Thesis | | 1978 |
| The Irish experience of insurgency and counter-insurgency since 1919 | O'Halpin, Eunan | Article in Book | | 2006 |
| The Military Service Pensions Project and Irish history : a personal perspective | O'Halpin, Eunan | Article in Book | | 2012 |
| The Second World War and Ireland | O'Halpin, Eunan | Article in Book | | 2014 |
| The secret service vote and Ireland, 1868-1922 | O'Halpin, Eunan | Article in Journal | | 1983 |
| The system of city and county management | O'Halpin, Eunan | Article in Book | | 2001 |