Residents of Dereham — Sub-district A, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 6 | oconnor | edward | M | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 203 |
| 7 | oconnor | francis | M | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 203 |
| 8 | oconnor | james | M | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 203 |
| 5 | oconnor | jane | F | 33 | Roman Catholic | Irish | Ontario | No Occupation Listed | 203 |
| 4 | oconnor | william | M | 35 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 203 |
| 9 | oconnor | william | M | 0 | Roman Catholic | Irish | Ontario | No Occupation Listed | 203 |
| 17 | oleo | norman | M | 66 | Baptist | Scottish | United States | No Occupation Listed | 219 |
| 18 | oleo | sarah | F | 60 | Baptist | English | United States | No Occupation Listed | 219 |
| 4 | omara | daniel | M | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 8 | omara | edward | M | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 1 | omara | ellen | F | 41 | Roman Catholic | Irish | Ireland | No Occupation Listed | 61 |
| 5 | omara | john | M | 14 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 9 | omara | joseph | M | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 10 | omara | mary | F | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 3 | omara | michael | M | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 7 | omara | patrick | M | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 2 | omara | thomas | M | 20 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 6 | omara | william | M | 11 | Roman Catholic | Irish | Ontario | No Occupation Listed | 61 |
| 25 | omarra | john | M | 53 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 61 |
| 7 | oneil | elizabeth | F | 23 | Roman Catholic | Irish | Ontario | No Occupation Listed | 23 |
| 6 | oneil | john | M | 29 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 23 |
| 8 | oneil | mary | F | 0 | Roman Catholic | Irish | Ontario | No Occupation Listed | 23 |
| 2 | osterancher | paul | M | 24 | Methodist | Canadian | Ontario | Farmers, general and nfs | 108 |
| 1 | ostrancher | arthur | M | 28 | Methodist | Canadian | Ontario | Labourers nfs | 108 |
| 4 | ostrancher | emma | F | 15 | Methodist | Canadian | Ontario | No Occupation Listed | 108 |
| 24 | ostrancher | henry | M | 64 | Methodist | Canadian | Ontario | Farmers, general and nfs | 108 |
| 25 | ostrancher | margaret | F | 60 | Methodist | Irish | Ireland | No Occupation Listed | 108 |
| 3 | ostrancher | william | M | 19 | Methodist | Canadian | Ontario | No Occupation Listed | 108 |
| 24 | ostranchez | fred | M | 7 | Baptist | Canadian | Ontario | No Occupation Listed | 55 |
| 21 | ostranchez | james | M | 47 | Baptist | American | Ontario | Labourers nfs | 55 |
| 22 | ostranchez | mary | F | 39 | Anglican | Scottish | Scotland | No Occupation Listed | 55 |
| 25 | ostranchez | mary | F | 23 | Baptist | Canadian | Ontario | No Occupation Listed | 55 |
| 23 | ostranchez | thades | M | 9 | Baptist | Canadian | Ontario | No Occupation Listed | 55 |
| 24 | ostrander | bell | F | 31 | Anglican | English | Ontario | No Occupation Listed | 121 |
| 2 | ostrander | charles | M | 4 | Anglican | Canadian | Ontario | No Occupation Listed | 121 |
| 3 | ostrander | elizabeth | F | 0 | Anglican | Canadian | Ontario | No Occupation Listed | 121 |
| 25 | ostrander | kathrin | F | 10 | Anglican | Canadian | Ontario | No Occupation Listed | 121 |
| 1 | ostrander | milton | M | 7 | Anglican | Canadian | Ontario | No Occupation Listed | 121 |
| 23 | ostrander | russel | M | 34 | Anglican | Canadian | Ontario | Farmers, general and nfs | 121 |