Residents of Millbrook, VL — Sub-district E, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 17 | oakes | samuel | M | 12 | Methodist | Irish | Ontario | No Occupation Listed | 122 |
| 21 | oconnor | agness | F | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 123 |
| 18 | oconnor | john | M | 38 | Roman Catholic | Irish | England | Bookkeepers nfs | 123 |
| 22 | oconnor | mable | F | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 123 |
| 19 | oconnor | margaret | F | 30 | Roman Catholic | Irish | Ontario | No Occupation Listed | 123 |
| 20 | oconnor | mary | F | 5 | Roman Catholic | Irish | Ontario | No Occupation Listed | 123 |
| 18 | oliver | elizabeth | F | 13 | Adventist Family | English | Ontario | No Occupation Listed | 88 |
| 17 | oliver | margaret | F | 33 | Adventist Family | English | Ontario | No Occupation Listed | 88 |
| 17 | oliver | matilda | F | 80 | Methodist | English | England | No Occupation Listed | 170 |
| 19 | oliver | phillip | M | 3 | Adventist Family | English | Ontario | No Occupation Listed | 88 |
| 16 | oliver | thomas | M | 44 | Adventist Family | English | England | Carpenters | 88 |
| 16 | oliver | zarachias | M | 80 | Methodist | English | England | No Occupation Listed | 170 |
| 2 | orr | alace | F | 16 | Methodist | Irish | Ontario | Milliners | 168 |
| 1 | orr | albert | M | 19 | Methodist | Irish | Ontario | Blacksmiths | 168 |
| 5 | orr | elizabeth | F | 7 | Methodist | Irish | Ontario | No Occupation Listed | 168 |
| 3 | orr | hanah | F | 13 | Methodist | Irish | Ontario | No Occupation Listed | 168 |
| 6 | orr | lora | F | 5 | Methodist | Irish | Ontario | No Occupation Listed | 168 |
| 6 | orr | margaret | F | 21 | Methodist | Irish | Ontario | No Occupation Listed | 77 |
| 24 | orr | mary | F | 41 | Methodist | English | Ontario | No Occupation Listed | 168 |
| 4 | orr | mary | F | 11 | Methodist | Irish | Ontario | No Occupation Listed | 168 |
| 23 | orr | william | M | 51 | Methodist | Irish | Ontario | Carpenters | 168 |
| 25 | orr | william | M | 21 | Methodist | Irish | Ontario | Clerks in shops and stores | 168 |