Residents of Tecumseth — Sub-district A, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 22 | obrien | catherine | F | 38 | Roman Catholic | Irish | Ontario | No Occupation Listed | 318 |
| 15 | obrien | chalotte | F | 24 | Roman Catholic | Irish | Ontario | No Occupation Listed | 107 |
| 12 | obrien | elisabeth | F | 74 | Roman Catholic | Irish | Ireland | No Occupation Listed | 107 |
| 14 | obrien | eliza | F | 25 | Roman Catholic | Irish | Ontario | No Occupation Listed | 107 |
| 25 | obrien | ellen | F | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 318 |
| 13 | obrien | euphema | F | 1 | Presbyterian | Irish | Ontario | No Occupation Listed | 159 |
| 11 | obrien | euphemia | F | 26 | Presbyterian | Scottish | Scotland | No Occupation Listed | 159 |
| 13 | obrien | james | M | 27 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 107 |
| 20 | obrien | john | M | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 102 |
| 24 | obrien | john | M | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 318 |
| 22 | obrien | john | M | 48 | Roman Catholic | Irish | Ontario | Labourers nfs | 359 |
| 19 | obrien | mary | F | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 102 |
| 23 | obrien | mary | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 318 |
| 23 | obrien | mary | F | 45 | Roman Catholic | Irish | Ireland | No Occupation Listed | 359 |
| 25 | obrien | mary | F | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 359 |
| 18 | obrien | morgan | M | 28 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 102 |
| 11 | obrien | morgan | M | 75 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 107 |
| 24 | obrien | smith | M | 15 | Roman Catholic | Irish | United States | No Occupation Listed | 359 |
| 10 | obrien | thomas | M | 34 | Roman Catholic | Irish | Ontario | Carpenters | 159 |
| 12 | obrien | vivian | M | 4 | Presbyterian | Irish | Ontario | No Occupation Listed | 159 |
| 21 | obrien | william | M | 40 | Roman Catholic | Irish | Ontario | Carpenters | 318 |
| 1 | obrien | william | M | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 318 |
| 9 | obrine | ann | F | 14 | Roman Catholic | Irish | Ireland | No Occupation Listed | 151 |
| 8 | obrine | catherine | F | 38 | Roman Catholic | Irish | Ireland | No Occupation Listed | 151 |
| 7 | obrine | john | M | 40 | Roman Catholic | Irish | Ireland | Mason nfs or combined | 151 |
| 19 | ocalahan | ellen | F | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 95 |
| 16 | ocalahan | francis | M | 44 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 95 |
| 18 | ocalahan | james | M | 22 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 95 |
| 17 | ocalahan | mary | F | 46 | Roman Catholic | Irish | Ontario | No Occupation Listed | 95 |
| 13 | ocallahan | andrew | M | 41 | Roman Catholic | Irish | Ontario | No Occupation Listed | 347 |
| 14 | ocallahan | bridget | F | 39 | Roman Catholic | Irish | Ontario | No Occupation Listed | 347 |
| 15 | ocallahan | james | M | 13 | Roman Catholic | Irish | Ontario | No Occupation Listed | 347 |
| 20 | ohara | bernard | M | 19 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 40 |
| 3 | ohara | bridget | F | 23 | Roman Catholic | Irish | United States | No Occupation Listed | 196 |
| 2 | ohara | catharin | F | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 25 | ohara | elizabeth | F | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 18 | ohara | john | M | 44 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 40 |
| 21 | ohara | john | M | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 2 | ohara | john | M | 28 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 196 |
| 5 | ohara | john | M | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 196 |
| 1 | ohara | julia | F | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 4 | ohara | julia | F | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 196 |
| 24 | ohara | mackay | M | 11 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 22 | ohara | martin | M | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 19 | ohara | mary | F | 44 | Roman Catholic | Irish | Ireland | No Occupation Listed | 40 |
| 23 | ohara | thomas | M | 13 | Roman Catholic | Irish | Ontario | No Occupation Listed | 40 |
| 13 | oharra | ada | F | 24 | Methodist | Irish | Ontario | Milliners | 340 |
| 22 | oleary | agnes | F | 7 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 13 | oleary | ann | F | 0 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 17 | oleary | anne | F | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 15 | oleary | catherine | F | 39 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 6 | oleary | daniel | M | 40 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 86 |
| 11 | oleary | daniel | M | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 18 | oleary | daniel | M | 28 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 22 |
| 20 | oleary | francis | M | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 16 | oleary | james | M | 18 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 84 |
| 14 | oleary | john | M | 50 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 84 |
| 19 | oleary | john | M | 13 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 18 | oleary | maggie | F | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 9 | oleary | margret | F | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 10 | oleary | micheal | M | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 21 | oleary | minnie | F | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 7 | oleary | norah | F | 33 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 8 | oleary | patrick | M | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 14 | oleary | patrick | M | 70 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 86 |
| 23 | oleary | thomas | M | 0 | Roman Catholic | Irish | Ontario | No Occupation Listed | 84 |
| 12 | oleary | william | M | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 86 |
| 9 | oneil | mary | F | 49 | Roman Catholic | Irish | Ireland | No Occupation Listed | 158 |
| 8 | oneil | thomas | M | 58 | Roman Catholic | Irish | Ireland | Labourers nfs | 158 |
| 21 | oram | fredde | M | 18 | Quaker/Society of Friends | English | England | river drivers | 126 |
| 25 | oughton | euriah | M | 6 | Anglican | English | Ontario | No Occupation Listed | 26 |
| 6 | oughton | stella | F | 8 | Presbyterian | English | Ontario | No Occupation Listed | 27 |
| 21 | oums | george | M | 18 | Methodist | English | Ontario | Coopers etc. | 309 |
| 18 | oums | isaac | M | 58 | Methodist | English | United States | Coopers etc. | 309 |
| 25 | oums | jacob | M | 36 | Anglican | English | Ontario | Labourers nfs | 303 |
| 20 | oums | lucinda | F | 22 | Methodist | English | United States | No Occupation Listed | 309 |
| 19 | oums | susan | F | 55 | Methodist | English | United States | No Occupation Listed | 309 |