| An unpublished letter from Charles I to the marquis of Ormonde | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1921 |
| Athlone Castle : its early history, with notes on some neighbouring castles | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1907 |
| Castrum Keyvini : Castlekevin | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1908 |
| Charters of Earl Richard Marshall of the forests of Ross and Taghmon | | Article in Journal | | 1934 |
| Dundrum Castle, County Down, identified with the 'Castrum de Rath' | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1909 |
| Ireland to 1315 | Orpen, G. H. (Goddard Henry) | Article in Book | | 1932 |
| Ireland under the Normans, 1169-1333 | Duffy, SeánOrpen, G. H. (Goddard Henry) | Monograph or Collective Volume | Four Courts | 2005 |
| Ireland under the Normans, vols. 1-2 : 1169-1216; vols. 3-4 : 1216-1333. 4 vols. | Orpen, G. H. (Goddard Henry) | Monograph or Collective Volume | | 1911 |
| Ireland, 1315-c.1485 | Orpen, G. H. (Goddard Henry) | Article in Book | | 1936 |
| Mote and bretesche building in Ireland | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1906 |
| Motes and Norman castles in Ireland. Parts 1-2 | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1907 |
| Motes and Norman castles in Ossory | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1909 |
| New Ross in the thirteenth century : an address delivered before the New Ross Literary Society | Orpen, G. H. (Goddard Henry) | Monograph or Collective Volume | | 1911 |
| Novum Castrum McKynegan, Newcastle, County Wicklow | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1908 |
| Ptolemy's map of Ireland | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1894 |
| Richard de Burgh and the conquest of Connaught | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1911 |
| Some Irish Cistercian documents | | Article in Journal | | 1913 |
| Song of Dermot and the earl, an old French poem | | Monograph or Collective Volume | | 1892 |
| The battle of Dundonell (Baginbun), A.D. 1170 | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1904 |
| The castle of Raymond le Gros at Fodredunolan | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1906 |
| The earldom of Ulster | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1921 |
| The effects of Norman rule in Ireland, 1169-1333 | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1914 |
| The effects of Norman rule in Ireland, 1169-1333 | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1913 |
| The Fitz Geralds, barons of Offaly | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1914 |
| The Normans in Tirowen and Tirconnell | Orpen, G. H. (Goddard Henry) | Article in Journal | | 1915 |
| The Scandinavian inroads and the movement towards Rome | Orpen, G. H. (Goddard Henry) | Article in Book | | 1934 |