| Town or | Townland or | Record | ||
| Last Name | First name | Village | Street | Number |
| O'Brien | Edward | Kilclief | 26 | |
| O'Brien | James H? | Ballintlieve | 4 | |
| O'Brien | Margaret | Kilclief | 14 | |
| O'Brien | Patrick | Kilclief | 14 | |
| O'Connor | Bernard | Legnagoppage | 7 | |
| O'Connor | Catherine | Struell | 1 | |
| O'Connor | Elizabeth | Struell | 1 | |
| O'Connor | Ellen | Legnagoppage | 7 | |
| O'Connor | Felix | Struell | 1 | |
| O'Connor | Felix | Struell | 1 | |
| O'Connor | Francis | Struell | 2 | |
| O'Connor | Isabella | Struell | 9 | |
| O'Connor | Mary | Legnagoppage | 7 | |
| O'Connor | Mary Anne | Struell | 1 | |
| O'Connor | Mary Isabella | Struell | 1 | |
| O'Connor | Mary Jane | Struell | 9 | |
| O'Connor | Patrick | Legnagoppage | 7 | |
| O'Connor | Rose | Struell | 1 | |
| O'Connor | Rose | Struell | 1 | |
| O'Connor | Susan | Downpatrick | Mary Street | 9 |
| O'Connor | Thomas | Struell | 9 | |
| O'Connor | Thomas James | Struell | 1 | |
| O'Donell | Rose | Quarter Cormick | 2 | |
| O'Donnell | Ellen | Grangicam | 10 | |
| O'Donnell | Ellen Mary | Grangicam | 10 | |
| O'Donnell | John | Grangicam | 10 | |
| O'Donnell | John Nath.. | Grangicam | 10 | |
| O'Donnell | Margaret J | Grangicam | 10 | |
| O'Driscoll | Alice | Downpatrick | Stream Street | 3 |
| O'Driscoll | Catherine | Downpatrick | Stream Street | 3 |
| O'Driscoll | Cecelia | Downpatrick | Stream Street | 3 |
| O'Driscoll | Edward | Russell's Quarter | 4 | |
| O'Driscoll | Margaret | Downpatrick | Stream Street | 3 |
| O'Flaherty | Elizabeth Matilda | Killough | Church Square | 10 |
| O'Flaherty | James | Killough | Church Square | 10 |
| O'Flynn | Mary J | Downpatrick | Scotch Street | 70 |
| O'Flynn | Patrick | Annacloy | 5 | |
| O'Hagan | Catherine | Dundrum | 5 | |
| O'Hagan | Charles | Dundrum | 5 | |
| O'Hagan | Ellen | Dundrum | 5 | |
| O'Hagen | Hanna | Downpatrick | Stream Street | 16 |
| O'Hagen | Hugh | Downpatrick | Stream Street | 16 |
| O'Hagen | James | Downpatrick | Circular Road | 12 |
| O'Hagen | James | Downpatrick | Stream Street | 16 |
| O'Hagen | John | Downpatrick | Circular Road | 12 |
| O'Hagen | Mary | Downpatrick | Circular Road | 12 |
| O'Hanlon | Catherine | Quarter Cormick | 2 | |
| O'Hanlon | James | Downpatrick | Fountain Street | 15 |
| O'Hanlon | James | Sheepland More | 2 | |
| O'Hanlon | John | Sheepland More | 2 | |
| O'Hanlon | Margaret | Downpatrick | Fountain Street | 15 |
| O'Hanlon | Mary | Ballymote Upper | 1 | |
| O'Hanlon | Mary A | Ballymote Upper | 1 | |
| O'Hanlon | Michael | Ballymote Upper | 1 | |
| O'Hanlon | Michael | Quarter Cormick | 2 | |
| O'Hanlon | Michael | Quarter Cormick | 2 | |
| O'Hanlon | Rose | Quarter Cormick | 2 | |
| O'Hanlon | Thos J | Ballymote Upper | 1 | |
| O'Hara | James | Dundrum | 13 | |
| O'Hare | Annie | Ballymenagh | 7 | |
| O'Hare | Bridget | Annsborough Town | 50 | |
| O'Hare | Bridget | Ballylough | 16 | |
| O'Hare | Daniel | Moneylane | 9 | |
| O'Hare | Edward J | Ballykeel | 19 | |
| O'Hare | Francis | Dundrum | 101 | |
| O'Hare | Francis | Ballylough | 10 | |
| O'Hare | Henry | Dundrum | 101 | |
| O'Hare | James | Ballintogher | 18 | |
| O'Hare | James | Russells Quarter South | 1 | |
| O'Hare | Jane | Moneylane | 9 | |
| O'Hare | John | Ballymenagh | 7 | |
| O'Hare | Margaret | Rathmullan Upper | 2 | |
| O'Hare | Margaret | Ballykeel | 19 | |
| O'Hare | Mary | Annsborough Town | 50 | |
| O'Hare | Mary | Ballymenagh | 7 | |
| O'Hare | Mary Jane | Ballykeel | 19 | |
| O'Hare | Patrick | Dundrum | 91 | |
| O'Hare | Patrick | Dundrum | 101 | |
| O'Hare | Patrick | Ballylough | 16 | |
| O'Hare | Patrick | Ballymenagh | 7 | |
| O'Hare | Rose | Dundrum | 101 | |
| O'Hare | Theresa | Clougher | 4 | |
| O'Hare | Thomas | Ballykeel | 19 | |
| O'Kane | Joseph | Strangford | 42 | |
| O'Kane | Patrick | Downpatrick | Circular Road | 20 |
| O'Kane? | Catherine | Downpatrick | Circular Road | 33 |
| O'Laverty* | John | Ballylucas | 4 | |
| Oliver | George | Killough | Castle Street | 14 |
| Oliver | William | Downpatrick | The Mall | 7 |
| Olpherts | ? Martina? W | Downpatrick | Irish Street | 56 |
| Olpherts | Jane Charlotte | Downpatrick | Irish Street | 56 |
| Olpherts | John W* | Downpatrick | Irish Street | 56 |
| Olpherts | Marian? Beatrice? W | Downpatrick | Irish Street | 56 |
| Olpherts | Mary W | Downpatrick | Irish Street | 56 |
| Olpherts | Maud Logbrants | Downpatrick | The Mall | 21 |
| O'Mealey | Ellen | Kilbride | 8 | |
| O'Mealey | Esther | Kilbride | 8 | |
| O'Mealey | Mary Ellen | Kilbride | 8 | |
| O'Mealey | Patrick | Kilbride | 8 | |
| O'Neil | Mary | Ballyculter Lower | 15 | |
| O'Neil | Terence ? | Ballyculter Lower | 15 | |
| O'Neill | Allis | Kilclief | 16 | |
| O'Neill | Anna Maria | Downpatrick | Circular Road | 33 |
| O'Neill | Annabella | Kilclief | 16 | |
| O'Neill | Dominick | Annsborough Town | 28 | |
| O'Neill | Eliza | Annsborough Town | 28 | |
| O'Neill | Ellen | Aughlisnafin | 39 | |
| O'Neill | George | Killough | Fisherman's Row | 24 |
| O'Neill | Hugh | Annsborough Town | 28* | |
| O'Neill | James | Annsborough Town | 28 | |
| O'Neill | James | Downpatrick | John Street | 40 |
| O'Neill | James | Kilclief | 16 | |
| O'Neill | James | Kilclief | 16 | |
| O'Neill | John | Aughlisnafin | 39 | |
| O'Neill | John | Aughlisnafin | 39 | |
| O'Neill | John | Ballyculter Lower | 10 | |
| O'Neill | Kathleen | Annsborough Town | 28 | |
| O'Neill | Mary | Ballybannon | 5 | |
| O'Neill | Mary Anne | Moneylane | 3 | |
| O'Neill | Mary Ellen | Aughlisnafin | 33 | |
| O'Neill | Minnie | Ballybannon | 5 | |
| O'Neill | Susan | Kilclief | 16 | |
| O'Pray | Elizabeth | Lisbane | 2 | |
| O'Pray | John | Lisbane | 2 | |
| O'Pray | Mary | Lisbane | 2 | |
| Oprey | Mary | Killough | Castle Street | 2 |
| Oprey | Robert | Killough | Castle Street | 2 |
| O'Prey | Alex John | Killough | Fisherman's Row | 34 |
| O'Prey | Bernard | Killough | Fisherman's Row | 34 |
| O'Prey | Bernard | Killough | Fisherman's Row | 34 |
| O'Prey | Daniel | Killough | Fisherman's Row | 34 |
| O'Prey | Daniel | Killough | Quay Lane | 5 |
| O'Prey | Daniel | Killough | Quay Lane | 5 |
| O'Prey | Elizabeth | Killough | Quay Lane | 5 |
| O'Prey | Elizabeth A? | Killough | Quay Lane | 5 |
| O'Prey | Hugh | Killough | Fisherman's Row | 34 |
| O'Prey | Margaret | Killough | Palatine Row | 5 |
| O'Prey | Mary | Killough | Palatine Row | 5 |
| O'Prey | Mary Ann | Killough | Fisherman's Row | 34 |
| O'Prey | Mary Jane | Killough | Quay Lane | 5 |
| O'Prey | Susanna R? | Killough | Quay Lane | 5 |
| O'Prey | William | Ballyrennan | 5 | |
| Orr | Catherine | Carrowcarlin | 1 | |
| Orr | Cecelia H? | Quoile | 5 | |
| Orr | David J | Ballyrenan | 1 | |
| Orr | Edith | Ballyculter Upper | 8 | |
| Orr | Edith | Ballyculter Upper | 8 | |
| Orr | Eliza | Audleystown | 10 | |
| Orr | Eliza J | Ballyrenan | 1 | |
| Orr | Elizabeth | Downpatrick | Church Street | 1 |
| Orr | Ellen | Quoile | 5 | |
| Orr | Enna | Ballyculter Upper | 8 | |
| Orr | Essie | Ballylenagh | 8 | |
| Orr | Essie | Ballylenagh | 8 | |
| Orr | Gearld | Grangicam | 1 | |
| Orr | Harriet | Ballyculter Upper | 8 | |
| Orr | Isabella | Grangicam | 5 | |
| Orr | Isabella | Ballyculter Lower | 17 | |
| Orr | Isabella | Ballyculter Upper | 20 | |
| Orr | James | Downpatrick | Market Street | 5 |
| Orr | James | Clonmaghery | 19 | |
| Orr | James | Ballyculter Upper | 8 | |
| Orr | John | Ballylenagh | 8 | |
| Orr | John R | Ballyrenan | 1 | |
| Orr | Joseph | Carrowcarlin | 1 | |
| Orr | Maggie | Downpatrick | Irish Street | 8 |
| Orr | Maggie J | Ballyrenan | 1 | |
| Orr | Mary | Grangicam | 1 | |
| Orr | Mary J | Ballyrenan | 1 | |
| Orr | Mathew Thos | Quoile | 5 | |
| Orr | Matthew | Downpatrick | Church Street | 1 |
| Orr | Maud E | Ballyrenan | 1 | |
| Orr | Moses | Ballyculter Upper | 19 | |
| Orr | Moses | Ballylenagh | 1 | |
| Orr | Rachael R? | Quoile | 5 | |
| Orr | Robert | Grangicam | 5 | |
| Orr | Samuel | Grangicam | 1 | |
| Orr | Samuel | Ballyrenan | 1 | |
| Orr | Samuel | Ballylenagh | 8 | |
| Orr | Samuel? | Ballyrenan | 1 | |
| Orr | Thomas | Grangicam | 1 | |
| Orr | Thomas | Russell's Quarter | 4 | |
| Orr | Thomas | Carrowcarlin | 1 | |
| Orr | Thomas | Carrowcarlin | 1 | |
| Orr | William | Welshestown | 15 | |
| Orr | William | Audleystown | 10 | |
| Orr | William | Ballyculter Lower | 17 | |
| Orr | William | Ballylenagh | 8 | |
| Orr | William J | Grangicam | 1 | |
| Orr | William J | Ballylenagh | 8 | |
| Orr | Willie | Grangicam | 5 | |
| Orr | Willie J | Ballyrenan | 1 | |
| O'Sullivan | Annie | Strangford | 56 | |
| O'Sullivan | Denis John | Strangford | 56 | |
| O'Sullivan | Elizabeth | Strangford | 56 | |
| O'Sullivan | Ellen | Strangford | 56 | |
| O'Sullivan | John | Strangford | 56 | |
| O'Sullivan | Mary Ellen | Strangford | 56 | |
| O'Sullivan | Thomas | Strangford | 56 | |
| O'Toole | Edward | Ballykinler Lower | 3 | |
| O'Toole | Susana | Ballykinler Lower | 3 | |
| O'Toole | William | Ballykinler Lower | 3 | |
| O'Toole | Wm J | Ballykinler Lower | 3 | |
| Otterson | Andrew | Killough | Palatine Row | 3 |
| Owens | Alice | Ballyhornan Village | 13 | |
| Owens | Edward | Castlemahon | 4 | |