Residents of Gwillimbury E — Sub-district F, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 3 | obee | ellen | F | 22 | Anglican | English | England | No Occupation Listed | 6 |
| 1 | obee | george | M | 67 | Anglican | English | England | Labourers nfs | 6 |
| 2 | obee | rachel | F | 59 | Anglican | English | England | No Occupation Listed | 6 |
| 4 | obee | william | M | 3 | Anglican | English | Ontario | No Occupation Listed | 6 |
| 5 | obee | | F | 0 | Anglican | English | Ontario | No Occupation Listed | 6 |
| 21 | obrien | james | M | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 149 |
| 22 | obrien | john | M | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 149 |
| 19 | obrien | louisa | F | 11 | Roman Catholic | Irish | Ontario | No Occupation Listed | 149 |
| 18 | obrien | margaret | F | 50 | Roman Catholic | Irish | Ireland | No Occupation Listed | 149 |
| 16 | obrien | margaret | F | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 16 | obrien | patrick | M | 66 | Roman Catholic | Irish | Ireland | Labourers nfs | 149 |
| 20 | obrien | teresia | F | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 149 |
| 17 | obrien | thomas | M | 19 | Roman Catholic | Irish | Ontario | Labourers nfs | 149 |
| 12 | obrun | esther | F | 47 | Presbyterian | Irish | Ontario | Dressmakers | 181 |
| 14 | obrun | john | M | 32 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 181 |
| 9 | obrun | nathaniel | M | 75 | Presbyterian | Irish | United States | Farmers, general and nfs | 181 |
| 10 | obrun | olive | F | 73 | Presbyterian | English | United States | No Occupation Listed | 181 |
| 11 | obrun | rebecca | F | 49 | Presbyterian | Irish | Ontario | No Occupation Listed | 181 |
| 13 | obrun | thomas | M | 35 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 181 |
| 9 | odlin | harriet | F | 53 | Anglican | Irish | England | No Occupation Listed | 74 |
| 11 | odlin | john | M | 16 | Presbyterian | Irish | Ontario | No Occupation Listed | 74 |
| 12 | odlin | mary | F | 14 | Presbyterian | Irish | Ontario | No Occupation Listed | 74 |
| 10 | odlin | sarah | F | 18 | Believer | Irish | Ontario | No Occupation Listed | 74 |
| 14 | oldam | james | M | 35 | Primitive Methodist | English | England | Servants nfs | 194 |
| 16 | oldam | john | M | 10 | Primitive Methodist | English | Ontario | No Occupation Listed | 194 |
| 17 | oldam | kate | F | 6 | Primitive Methodist | English | Ontario | No Occupation Listed | 194 |
| 18 | oldam | mary | F | 1 | Primitive Methodist | English | Ontario | No Occupation Listed | 194 |
| 15 | oldam | sarah | F | 24 | Primitive Methodist | Irish | Ireland | No Occupation Listed | 194 |
| 8 | oldham | ann | F | 10 | Primitive Methodist | English | England | No Occupation Listed | 230 |
| 7 | oldham | edward | M | 13 | Primitive Methodist | English | England | No Occupation Listed | 230 |
| 6 | oldham | jagger | M | 16 | Primitive Methodist | English | England | Farmers, general and nfs | 230 |
| 5 | oldham | james | M | 23 | Primitive Methodist | English | England | Farmers, general and nfs | 230 |
| 4 | oldham | nathan | M | 27 | Primitive Methodist | English | England | Farmers, general and nfs | 230 |
| 3 | oldham | susannah | F | 52 | Primitive Methodist | English | England | No Occupation Listed | 230 |
| 2 | oldham | william | M | 50 | Primitive Methodist | English | England | Farmers, general and nfs | 230 |
| 20 | oliver | harriet | F | 39 | Anglican | French | Ontario | No Occupation Listed | 179 |
| 21 | oliver | judith | F | 14 | Anglican | English | Ontario | No Occupation Listed | 179 |
| 22 | oliver | mary | F | 12 | Anglican | English | Ontario | No Occupation Listed | 179 |
| 23 | oliver | sarah | F | 8 | Anglican | English | Ontario | No Occupation Listed | 179 |
| 19 | oliver | thomas | M | 39 | Anglican | English | Ontario | Farmers, general and nfs | 179 |
| 3 | osborn | herbert | M | 4 | Anglican | English | Ontario | No Occupation Listed | 102 |
| 4 | osborn | james | M | 2 | Anglican | English | Ontario | No Occupation Listed | 102 |
| 1 | osborn | jane | F | 30 | Anglican | English | England | No Occupation Listed | 102 |
| 25 | osborn | richard | M | 29 | Anglican | English | England | Other agricultural and animal husbandry workers | 102 |
| 5 | osborn | walter | M | 0 | Anglican | English | Ontario | No Occupation Listed | 102 |
| 2 | osborn | william | M | 6 | Anglican | English | Ontario | No Occupation Listed | 102 |
| 20 | ough | carrie | F | 7 | Methodist | English | Ontario | No Occupation Listed | 61 |
| 21 | ough | clifford | M | 6 | Methodist | English | Ontario | No Occupation Listed | 61 |
| 19 | ough | elizabeth | F | 26 | Methodist | Irish | Ontario | No Occupation Listed | 61 |
| 22 | ough | elizabeth | F | 4 | Methodist | English | California | No Occupation Listed | 61 |
| 23 | ough | herbert | M | 2 | Methodist | English | California | No Occupation Listed | 61 |
| 18 | ough | john | M | 28 | Methodist | English | Ontario | Carpenters | 61 |
| 13 | ovigh | elizabeth | F | 21 | Methodist | English | Ontario | No Occupation Listed | 10 |
| 12 | ovigh | ellen | F | 34 | Methodist | Irish | Ontario | No Occupation Listed | 10 |
| 11 | ovigh | harris | M | 47 | Methodist | English | England | Farmers, general and nfs | 10 |
| 14 | ovigh | william | M | 19 | Methodist | English | Ontario | No Occupation Listed | 10 |
| 23 | ovikson | albert | M | 20 | Presbyterian | Scottish | Scotland | Farmers, general and nfs | 210 |
| 20 | ovikson | andrew | M | 36 | Presbyterian | Scottish | England | Farmers, general and nfs | 210 |
| 21 | ovikson | charlotte | F | 32 | Presbyterian | Scottish | England | No Occupation Listed | 210 |
| 22 | ovikson | elizabeth | F | 73 | Presbyterian | Scottish | Scotland | No Occupation Listed | 210 |
| 25 | oxtaby | catherine | F | 3 | Presbyterian | English | Ontario | No Occupation Listed | 119 |
| 21 | oxtaby | christopher | M | 50 | Presbyterian | English | Ontario | Farmers, general and nfs | 119 |
| 22 | oxtaby | hannah | F | 40 | Presbyterian | Dutch | Ontario | No Occupation Listed | 119 |
| 24 | oxtaby | julia | F | 8 | Presbyterian | English | Ontario | No Occupation Listed | 119 |
| 23 | oxtaby | mary | F | 13 | Presbyterian | English | California | No Occupation Listed | 119 |