| A 14th-century Meath estate acquired too soon: Golding of Churchtown | O'Brien, Niall C. E. J. | Article in Journal | | 2019 |
| Clashmore and Cappagh in Medieval Times | O'Brien, Niall C. E. J. | Article in Journal | | 2018 |
| Clonmel apprentices in Bristol, 1541-1566 | O'Brien, Niall C. E. J. | Article in Journal | | 2019 |
| Clonmore Rectory in 1407 and doubts on the Calendar of Papal Letters | O'Brien, Niall C. E. J. | Article in Journal | | 2017 |
| Educated clergy in medieval Leighlin | O'Brien, Niall C. E. J. | Article in Journal | | 2020 |
| Holy Cross and Kilcooley: Two Holy Cross abbeys in Tipperary | O'Brien, Niall C. E. J. | Article in Journal | | 2023 |
| Jerpoint Abbey in the Calendar of Papal Registers | O'Brien, Niall C. E. J. | Article in Journal | | 2016 |
| KIlkenny apprentices at Bristol, 1532-1545 | O'Brien, Niall C. E. J. | Article in Journal | | 2018 |
| Medieval Kilmeaden parish clergy: rectors or vicars? | O'Brien, Niall C. E. J. | Article in Journal | | 2019 |
| Royal constables of Cashel Castle, Co. Tipperary | O'Brien, Niall C. E. J. | Article in Journal | | 2013 |
| The Chancellorship of medieval Leighlin | O'Brien, Niall C. E. J. | Article in Journal | | 2019 |
| The medieval county of Roscommon | O'Brien, Niall C. E. J. | Article in Journal | | 2019 |
| Ullard Prebend in fifteenth-century Laighlin | O'Brien, Niall C. E. J. | Article in Journal | | 2018 |