| I name this ship .... | O'Brien, Seán | Article in Journal | | 1996 |
| Irish Americans in the Confederate Army | O'Brien, Sean Michael | Monograph or Collective Volume | McFarland & Company, Inc. | 2013 |
| Selected megalithic field monuments in east Waterford | O'Brien, Seán | Article in Book | | 2005 |
| The book of Finglas | O'Brien, Seán | Monograph or Collective Volume | Kincora Press | 1980 |
| The Butlers of Lower Grange, viscounts Galmoy | O'Brien, Seán | Article in Journal | | 1964 |
| The prison writing of Michael Davitt | O'Brien, Sean T. | Article in Journal | | 2010 |
| The tithe war 1831-1838 | O'Brien, Seán | Article in Journal | | 1993 |