Records Browser
| Census subdivision | Census division | Province | Year | Total population |
|---|---|---|---|---|
| Oakland | Brant | ON | 1851 | 840 |
| Oneida | Haldimand | ON | 1851 | 2817 |
| Onondaga | Brant | ON | 1851 | 1858 |
| Ontario | Kingston, City | ON | 1851 | 1520 |
| Ops | Victoria | ON | 1851 | 2512 |
| Orillia and Matchedash | Simcoe | ON | 1851 | 725 |
| Oro | Simcoe | ON | 1851 | 2027 |
| Osgood | Carleton | ON | 1851 | 3050 |
| Oshawa | Ontario | ON | 1851 | 1142 |
| Osnabruck | Stormont | ON | 1851 | 4699 |