Residents of Muskoka — Sub-district C, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 21 | obrien | annie | F | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 170 |
| 23 | obrien | edward | M | 5 | Roman Catholic | Irish | Ontario | No Occupation Listed | 170 |
| 25 | obrien | james | M | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 170 |
| 19 | obrien | john | M | 34 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 170 |
| 24 | obrien | john | M | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 170 |
| 20 | obrien | margaret | F | 30 | Roman Catholic | English | England | No Occupation Listed | 170 |
| 22 | obrien | margaret | F | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 170 |