| The Vita Columbani in Merovingian Gaul A O'Hara Early Medieval Europe 17 (2), 126-153, 2009 | 53 | 2009 |
| Columbanus and the peoples of post-Roman Europe A O'Hara Oxford University Press, 2018 | 26 | 2018 |
| Jonas of Bobbio and the legacy of Columbanus: sanctity and community in the seventh century A O'Hara Oxford University Press, 2018 | 23 | 2018 |
| Jonas of Bobbio: Life of Columbanus, Life of John of Réomé, and Life of Vedast A O'Hara, I Wood Liverpool University Press, 2017 | 20 | 2017 |
| Constructing a saint: the legend of St Sunniva in twelfth-century Norway A O'Hara Viking and Medieval Scandinavia, 105-121, 2009 | 20 | 2009 |
| Columbanus ad Locum: The Establishment of the Monastic Foundations A O’Hara Peritia 26, 143-170, 2015 | 11 | 2015 |
| Patria, peregrinatio, and paenitentia: Identities of Alienation in the Seventh Century A O’Hara Post-Roman Transitions: Christian and Barbarian Identities in the Early …, 2013 | 8 | 2013 |
| Death and the Afterlife in Jonas of Bobbio’s Vita Columbani A O’Hara Studies in Church History 45, 64-73, 2009 | 7 | 2009 |
| Aristocratic and Monastic Conflict in Tenth-Century Italy: the Case of Bobbio and the Miracula Sancti Columbani A O’Hara, F Taylor Viator 44 (3), 43-61, 2013 | 6 | 2013 |
| Jonas of Bobbio A O’Hara, I Wood Life of Columbanus, Life of John of Réomé, and Life of Vedast. Liverpool …, 2017 | 5 | 2017 |
| Jonas of Bobbio, Marchiennes-Hamage, and the Regula cuiusdam ad virgines A O’Hara Colomban et son influence: Moines et monastères du haut Moyen Âge en Europe …, 2018 | 3 | 2018 |
| Saint Columbanus: Selected Writings A O'Hara Veritas Publications, 2015 | 3 | 2015 |
| The Babenbergs and the Cult of St. Coloman A O’Hara The Journal of Medieval Latin 25, 131-172, 2015 | 3 | 2015 |
| Jonas of Bobbio and the'Vita Columbani': sanctity and community in the seventh century A O'Hara University of St Andrews, 2009 | 3 | 2009 |
| 17.03. 08, Flechner and Meeder, eds., The Irish in Early Medieval Europe A O’Hara The Medieval Review, 2017 | 2 | 2017 |
| A lacuna in Irish historiography: the Irish peregrini from Eoin MacNeill to The Cambridge history of Ireland and beyond A O'Hara Irish Historical Studies 47, 1-18, 2023 | 1 | 2023 |
| Book Review: Maynooth College Reflects on Covid-19: New Realities in Uncertain Times A O’Hara Irish Theological Quarterly 87 (3), 243-245, 2022 | | 2022 |
| From Sithiu to Saint-Bertin. Hagiographic Exegesis and Collective Memory in the Early Medieval Cults of Omer and Bertin A O'Hara, D Defries HISTORISCHE ZEITSCHRIFT 313 (1), 195-197, 2021 | | 2021 |
| St. Sunniva: Irsk Dronning, Norsk Vernehelgen: Irish Queen, Norwegian Patron Saint AT Hommedal, A O'Hara Alvheim et Eide akademisk forlag, 2021 | | 2021 |
| Life of Columbanus A O'Hara, IN Wood Translated texts for historians, 2017 | | 2017 |