| A Catholic merchant's bequest to the poor: James Fanning and his charitable bequest | Breen, Mary | Article in Journal | | 2016 |
| Kilkenny - a renaissance city? | Breen, Mary | Article in Journal | | 2015 |
| Religion and conflict in Danesfort | Breen, Mary | Article in Journal | | 1996 |
| Testimony in stone | Breen, Mary | Article in Journal | | 1992 |
| The annals of a Kilkenny tenant farming family | Breen, Mary | Article in Journal | | 1998 |
| The civil parish of Treadingstown | Breen, Mary | Article in Journal | | 1987 |
| The making and unmaking of an Irish woman of letters | Breen, Mary Catherine | Thesis | | |
| Waterford port and harbour, 1815-42 | Breen, Mary | Monograph or Collective Volume | Four Courts Press | 2019 |
| Whitfield Court, Co. Waterford: challenges and threats to an historic house | Breen, Mary | Article in Journal | | 2019 |