| 'A centre of turbulence and rioting' : the republican movement in Limerick, 1917-1918 | O'Callaghan, John | Article in Book | Mercier Press | 2011 |
| 16 lives : Con Colbert | O’Callaghan, John | Monograph or Collective Volume | O'Brien Press | 2015 |
| Buttevant Abbey | O'Callaghan, John | Article in Journal | | 1985 |
| County Limerick and the Irish revolution, 1913-21 | O'Callaghan, John | Thesis | | 2008 |
| Éigse Sliabh Rua Ui Dea | O'Callaghan, John | Article in Book | | 2001 |
| Fortified houses of the sixteenth century in south Wexford | O'Callaghan, John | Article in Journal | | 1980 |
| Fortified houses of the sixteenth century in south Wexford | Callaghan, John | Article in Journal | | 1980 |
| History of the Irish brigades in the service of France | Hally, P. J.O'Callaghan, John Cornelius, 1805-1883 | Monograph or Collective Volume | Irish University Press | 1969 |
| History of the Irish brigades in the service of France | Hally, P. J.O'Callaghan, John Cornelius, 1805-1883 | Monograph or Collective Volume | Cameron and Ferguson | 1870 |
| Limerick | O'Callaghan, John | Article in Book | | 2017 |
| Macariae excidium, or the destruction of Cyprus | O'Callaghan, John Cornelius, 1805-1883O'Kelly, Charles, 1621-1695 | Monograph or Collective Volume | | 1850 |
| Monksgrange : the home of Mr and Mrs Richards-Orpen | O'Callaghan, John | Article in Journal | | 1968 |
| Munster | O'Callaghan, John | Article in Book | | 2017 |
| Narratives of the occluded Irish diaspora : subversive voices | | Monograph or Collective Volume | Peter Lang | 2012 |
| Plassey's Gaels : a history of the GAA at NIHE, NCPE, Thomond College and the University of Limerick, 1972-2012 | O'Callaghan, John | Monograph or Collective Volume | Collins | 2013 |
| Politics, policy and history : history teaching in Irish secondary schools 1922-70 | O'Callaghan, John | Article in Journal | | 2004 |
| Politics, policy and history: History teaching in Irish secondary schools 1922-1970 | O'Callaghan, John
| Article in Journal | | 2011 |
| Republican administation of local government in Limerick, 1920-21 | O'Callaghan, John | Article in Journal | | 2005 |
| Revolutionary Limerick : the republican campaign for independence in Limerick, 1913-1921 | O'Callaghan, John | Monograph or Collective Volume | Irish Academic Press | 2010 |
| Teaching Irish independence : history of Irish schools, 1922-72 | O'Callaghan, John | Monograph or Collective Volume | Cambridge Scholars | 2009 |
| The battle for Kilmallock | O'Callaghan, John | Monograph or Collective Volume | Mercier Press | 2011 |
| The castle of the Deeps | O'Callaghan, John | Article in Journal | | 1969 |
| The Irish Revolution, 1912–23: Limerick | O'Callaghan, John | Monograph or Collective Volume | Four Courts | 2018 |
| The Limerick Volunteers and 1916 | O'Callaghan, John | Article in Book | | 2008 |
| The Mayo echosphere in 2019 (after Tim Robinson) | O'Callaghan, John | Article in Journal | | 2018 |
| Travelling in Duhallow before 1760 | O'Callaghan, John | Article in Journal | | 1993 |
| Vindiciarum Catholicorum Hiberniae authore Philopatro Irenaeo ad Alitophilum libri duo : quorum primus rerum in Hibernia gestarum ab anno 1641, ad annum 1649. verissimam & actorum publicorum fide munitam synopsim, secundus libelli famosi in Catholicas Hiberniae proceres, qui honestissimam cum regiarum partium hominibus pacem inierunt, accuratam confutationem continet | Callaghan, John, fl. 1650 | Monograph or Collective Volume | | 1650 |
| We were obliged to leave our beautiful home', protestant experiences of revolution in Limerick, 1912-1923 | O’Callaghan, John | Article in Book | | 2023 |
| West Mayo placenames : origin and meaning | O'Callaghan, John | Monograph or Collective Volume | Covie Publications and Recordings | 2024 |