Residents of Lanark — Sub-district D, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 21 | oconner | michael | M | 85 | Roman Catholic | Irish | Ireland | No Occupation Listed | 61 |
| 3 | oconnor | florence | M | 5 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 5 | oconnor | hortensia | F | 0 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 23 | oconnor | jane | F | 36 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 24 | oconnor | lizzie | F | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 2 | oconnor | mary | F | 7 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 25 | oconnor | micael | M | 13 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 4 | oconnor | teriessa | F | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 22 | oconnor | thomas | M | 50 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 65 |
| 1 | oconnor | thomas | M | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 65 |
| 25 | okief | margaret | F | 70 | Roman Catholic | Irish | Ontario | No Occupation Listed | 17 |
| 24 | okief | patrick | M | 65 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 17 |