Residents of Marlborough — Sub-district C, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 9 | obrien | daniel | M | 84 | Roman Catholic | Irish | Ireland | No Occupation Listed | 110 |
| 8 | obrien | jermiah | M | 32 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 110 |
| 10 | obrien | mary | F | 19 | Roman Catholic | Irish | Ontario | Teachers (unspecified) | 110 |
| 14 | oday | ellen | F | 50 | Roman Catholic | Irish | Ireland | No Occupation Listed | 85 |
| 15 | oday | ellen | F | 20 | Roman Catholic | Irish | Ontario | No Occupation Listed | 85 |
| 17 | oday | mary | F | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 85 |
| 16 | oday | patrick | M | 18 | Roman Catholic | Irish | Ontario | No Occupation Listed | 85 |
| 13 | oday | simon | M | 59 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 85 |
| 6 | odonald | catherine | F | 40 | Roman Catholic | Irish | Ireland | No Occupation Listed | 129 |
| 24 | oneil | agnes | F | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 27 |
| 15 | oneil | annie | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 99 |
| 24 | oneil | bridget | F | 65 | Roman Catholic | Irish | Ireland | No Occupation Listed | 104 |
| 2 | oneil | catharine | F | 23 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 18 | oneil | catherine | F | 66 | Roman Catholic | Irish | Ireland | No Occupation Listed | 27 |
| 22 | oneil | charles | M | 21 | Roman Catholic | Irish | Ontario | No Occupation Listed | 27 |
| 21 | oneil | cornelious | M | 68 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 108 |
| 19 | oneil | cornelious | M | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |
| 20 | oneil | daniel | M | 28 | Roman Catholic | Irish | Ontario | No Occupation Listed | 27 |
| 21 | oneil | dennis | M | 26 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 27 |
| 11 | oneil | dennis | M | 24 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 99 |
| 23 | oneil | dennis | M | 70 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 104 |
| 25 | oneil | dennis | M | 23 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 104 |
| 15 | oneil | dennis | M | 21 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 111 |
| 23 | oneil | eliza | F | 14 | Roman Catholic | Irish | Ontario | No Occupation Listed | 108 |
| 10 | oneil | elizabeth | F | 70 | Roman Catholic | Irish | Ireland | No Occupation Listed | 118 |
| 12 | oneil | ellen | F | 22 | Roman Catholic | Irish | Ontario | No Occupation Listed | 99 |
| 12 | oneil | ellen | F | 50 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |
| 18 | oneil | ellen | F | 16 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |
| 25 | oneil | geramiah | M | 11 | Roman Catholic | Irish | Ontario | No Occupation Listed | 108 |
| 7 | oneil | hanora | F | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 93 |
| 1 | oneil | honora | F | 27 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 5 | oneil | james | M | 34 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 93 |
| 9 | oneil | james | M | 45 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 118 |
| 11 | oneil | james | M | 61 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 111 |
| 17 | oneil | james | M | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |
| 22 | oneil | johana | F | 64 | Roman Catholic | Irish | Ireland | No Occupation Listed | 108 |
| 14 | oneil | john | M | 18 | Roman Catholic | Irish | Ontario | No Occupation Listed | 99 |
| 14 | oneil | john | M | 23 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 111 |
| 6 | oneil | margarette | F | 35 | Roman Catholic | Irish | Ontario | No Occupation Listed | 93 |
| 9 | oneil | margarette | F | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 93 |
| 24 | oneil | margret | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 108 |
| 10 | oneil | marry | F | 56 | Roman Catholic | Irish | Ireland | No Occupation Listed | 99 |
| 23 | oneil | mary | F | 40 | Roman Catholic | Irish | Ontario | No Occupation Listed | 27 |
| 13 | oneil | mary | F | 25 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |
| 8 | oneil | michael | M | 4 | Roman Catholic | Irish | Ontario | No Occupation Listed | 93 |
| 13 | oneil | norah | F | 20 | Roman Catholic | Irish | Ontario | No Occupation Listed | 99 |
| 20 | oneil | sarah | F | 7 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |
| 19 | oneil | thomas | M | 31 | Roman Catholic | Irish | Ontario | No Occupation Listed | 27 |
| 16 | oneil | timothy | M | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 111 |