Residents of Seaforth, Village — Sub-district F, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 2 | oburn | catherine | F | 21 | Roman Catholic | Irish | Ontario | No Occupation Listed | 289 |
| 23 | oconnor | agnes | F | 7 | Roman Catholic | Irish | Ontario | No Occupation Listed | 276 |
| 21 | oconnor | mary | F | 35 | Roman Catholic | Irish | Ontario | No Occupation Listed | 276 |
| 22 | oconnor | therese | F | 20 | Roman Catholic | Irish | Ontario | No Occupation Listed | 276 |
| 20 | oconnor | thomas | M | 40 | Roman Catholic | Irish | Ireland | Agent nfs | 276 |
| 7 | offord | george | M | 28 | Methodist | English | Ontario | Dealer, merchant etc. (Wholesale & retail trade) | 126 |
| 16 | ohara | ellen | F | 22 | Roman Catholic | Irish | Ontario | Domestic and House Servants | 357 |
| 9 | okemp | jennet | F | 25 | Presbyterian | Blank | Ontario | No Occupation Listed | 153 |
| 10 | okemp | mary | F | 3 | Presbyterian | English | Ontario | No Occupation Listed | 153 |
| 8 | okemp | thomas | M | 32 | Anglican | English | England | Superintendents and managers, nfs | 153 |
| 17 | oliver | w | M | 47 | Anglican | English | Ontario | Saddler and harness maker | 306 |
| 3 | olney | amanda | F | 23 | Methodist | Irish | Ontario | Hairdressers | 207 |
| 20 | orourk | mary | F | 19 | Roman Catholic | Irish | Ontario | Domestic and House Servants | 416 |
| 1 | oshea | p | M | 39 | Roman Catholic | Irish | Ireland | Ambiguous responses | 303 |
| 22 | owens | margaret | F | 23 | Anglican | Irish | Ontario | No Occupation Listed | 19 |