| Name | Graveyard / Cemetery / Burial Ground |
| | |
| O'Flanagan James | Irvinestown Old Graveyard County Fermanagh |
| O'Flanagan Mr | Old Rossory Graveyard County Fermanagh |
| Ogle Adam | Tubrid Church of Ireland County Fermanagh |
| Ogle Barbara | Tubrid Church of Ireland County Fermanagh |
| Ogle Elizabeth | Tubrid Church of Ireland County Fermanagh |
| Ogle George | Tubrid Church of Ireland County Fermanagh |
| Ogle Gladys E | Tubrid Church of Ireland County Fermanagh |
| O'Gorman Teresa J | Boho RC Church County Fermanagh |
| O'Hara Miss | Aghavea Church of Ireland County Fermanagh |
| O'Hara Oyne | Aghavea Church of Ireland County Fermanagh |
| Ohoyn Bryan | Pubble Churchyard County Fermanagh |
| Oldfield R H | Irvinestown Church of Ireland County Fermanagh |
| O'Leary J N | Irvinestown RC Church County Fermanagh |
| Oltaghon Denis | Aghalurcher Old Graveyard County Fermanagh |
| O'Neil Henry | Keenaghan RC Abbey County Fermanagh |
| O'Neile Barnaby | Keenaghan RC Abbey County Fermanagh |
| O'Neile Henry | Keenaghan RC Abbey County Fermanagh |
| O'Neill Henry | Rosslea RC Church County Fermanagh |
| O'Neill Catherine | Bellanaleck RC Church County Fermanagh |
| O'Neill Mary | Mullaghdun RC Church County Fermanagh |
| O'Neill Nicholas | Killesher Chapel of Ease County Fermanagh |
| O'Neill Revd Patrick | Tempo RC Church County Fermanagh |
| Onison Oyne | Killesher Chapel of Ease County Fermanagh |
| O'Prey John | Bellanaleck RC Church County Fermanagh |
| O'Prey Mary J | Bellanaleck RC Church County Fermanagh |
| O'Reilly Anne | Donagh Old Graveyard County Fermanagh |
| O'Reilly Thomas | Donagh Old Graveyard County Fermanagh |
| O'Rourke James | Belleek RC Church County Fermanagh |
| Orr J S | Irvinestown Church of Ireland County Fermanagh |
| Ovens Edward W | Derrygonnelly Church of Ireland County Fermanagh |
| Ovens Hugh | Derrygonnelly Old Graveyard County Fermanagh |
| Ovens James | Derrygonnelly Old Graveyard County Fermanagh |
| Ovens James | Derrygonnelly Old Graveyard County Fermanagh |
| Ovens James M | Derrygonnelly Old Graveyard County Fermanagh |
| Ovens John | Slavin Church of Ireland County Fermanagh |
| Ovens Margaret | Slavin Church of Ireland County Fermanagh |
| Ovens Margaret E | Derrygonnelly Church of Ireland County Fermanagh |
| Ovens Thomas | Derrygonnelly Old Graveyard County Fermanagh |
| Ovens Revd William | Derrygonnelly Old Graveyard County Fermanagh |
| Owen Anney | Brookeborough RC Church County Fermanagh |
| Owen Elizabeth | Aghavea Church of Ireland County Fermanagh |
| Owen Joseph | Aghavea Church of Ireland County Fermanagh |
| Owen Margaret | Aghavea Church of Ireland County Fermanagh |
| Owens Anne | Bellanaleck RC Church County Fermanagh |
| Owens Annie | Bellanaleck RC Church County Fermanagh |
| Owens Brian | Ardess Church of Ireland County Fermanagh |
| Owens Catherine | Brookeborough RC Church County Fermanagh |
| Owens Catherine | Brookeborough RC Church County Fermanagh |
| Owens Catherine | Brookeborough RC Church County Fermanagh |
| Owens Damian | Bellanaleck RC Church County Fermanagh |