Residents of Sidney — Sub-district A, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 14 | obryan | catherine | F | 27 | Roman Catholic | Irish | Ontario | No Occupation Listed | 162 |
| 17 | obryan | catherine | F | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 162 |
| 15 | obryan | mary | F | 6 | Roman Catholic | Irish | Ontario | No Occupation Listed | 162 |
| 16 | obryan | teressa | F | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 162 |
| 1 | ohara | ann | F | 11 | Roman Catholic | Irish | Ontario | No Occupation Listed | 34 |
| 25 | ohara | bridget | F | 16 | Roman Catholic | Irish | Ontario | No Occupation Listed | 34 |
| 3 | ohara | bridget | F | 45 | Roman Catholic | Irish | Ireland | No Occupation Listed | 254 |
| 8 | ohara | bridget | F | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 254 |
| 5 | ohara | charlie | M | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 254 |
| 6 | ohara | daniel | M | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 254 |
| 4 | ohara | edward | M | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 254 |
| 24 | ohara | mary | F | 43 | Roman Catholic | Irish | Ireland | No Occupation Listed | 34 |
| 2 | ohara | nellie | F | 5 | Roman Catholic | Irish | Ontario | No Occupation Listed | 34 |
| 23 | ohara | patrick | M | 43 | Roman Catholic | Irish | Ireland | Labourers nfs | 34 |
| 2 | ohara | thomas | M | 50 | Roman Catholic | Irish | Ireland | Labourers nfs | 254 |
| 23 | oliver | francis | M | 32 | Methodist | Irish | Ontario | Saddler and harness maker | 123 |
| 1 | oliver | francis | M | 80 | Methodist | Irish | Ireland | Boot and shoemakers and repairers | 124 |
| 2 | oliver | rachael | F | 75 | Methodist | Irish | Ireland | No Occupation Listed | 124 |
| 3 | oliver | rachael | F | 35 | Methodist | Irish | Ontario | No Occupation Listed | 124 |
| 8 | oliver | richard | M | 79 | Episcopal Methodist | English | England | Farmers, general and nfs | 45 |
| 24 | oliver | rumah | F | 30 | Methodist | German | Ontario | No Occupation Listed | 123 |
| 7 | oliver | susan | F | 70 | Episcopal Methodist | English | England | No Occupation Listed | 45 |
| 25 | oliver | thomas | M | 6 | Methodist | Irish | Ontario | No Occupation Listed | 123 |
| 6 | omeara | annie | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 51 |
| 5 | omeara | margaret | F | 22 | Roman Catholic | Irish | Ontario | Milliners | 51 |
| 4 | omeara | mary | F | 50 | Roman Catholic | Irish | Ireland | No Occupation Listed | 51 |
| 3 | omeara | michael | M | 50 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 51 |
| 7 | omeara | roderick | M | 9 | Roman Catholic | Irish | Ontario | No Occupation Listed | 51 |
| 11 | orme | mary | F | 18 | Episcopal Methodist | Scottish | Scotland | Servants nfs | 122 |
| 15 | orr | beatrice | F | 17 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 16 | orr | bob | M | 14 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 17 | orr | bruce | M | 11 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 13 | orr | easter | F | 48 | Episcopal Methodist | Irish | Ontario | No Occupation Listed | 214 |
| 14 | orr | emma | F | 22 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 20 | orr | florence | F | 5 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 19 | orr | harry | M | 7 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 12 | orr | john | M | 48 | Episcopal Methodist | Scottish | Ontario | Farmers, general and nfs | 214 |
| 18 | orr | may | F | 9 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 21 | orr | stella | F | 1 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 214 |
| 25 | ostrander | isiac | M | 26 | Episcopal Methodist | German | Ontario | Farmers, general and nfs | 8 |
| 1 | ostrander | june | F | 22 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 8 |
| 12 | ostrom | anna | F | 24 | Methodist | Irish | Ontario | No Occupation Listed | 89 |
| 6 | ostrom | burleigh | M | 22 | Methodist | German | Ontario | Bookkeepers nfs | 7 |
| 3 | ostrom | byron | M | 22 | Presbyterian | Dutch | Ontario | Dealer, merchant etc. (Wholesale & retail trade) | 110 |
| 13 | ostrom | catherine | F | 57 | Methodist | German | Ontario | No Occupation Listed | 89 |
| 11 | ostrom | charles | M | 36 | Methodist | German | Ontario | Farmers, general and nfs | 89 |
| 2 | ostrom | charlotte | F | 24 | Presbyterian | Dutch | Ontario | No Occupation Listed | 110 |
| 9 | ostrom | clara | F | 7 | Methodist | German | Ontario | No Occupation Listed | 88 |
| 24 | ostrom | daniel | M | 65 | Presbyterian | Dutch | Ontario | Butchers | 110 |
| 5 | ostrom | florence | F | 7 | Methodist | German | Ontario | No Occupation Listed | 96 |
| 3 | ostrom | george | M | 38 | Methodist | German | Ontario | Farmers, general and nfs | 96 |
| 8 | ostrom | hellen | F | 32 | Methodist | German | Ontario | No Occupation Listed | 88 |
| 19 | ostrom | isaac | M | 67 | Methodist | German | Ontario | Farmers, general and nfs | 100 |
| 7 | ostrom | john | M | 34 | Methodist | German | Ontario | Farmers, general and nfs | 88 |
| 4 | ostrom | luke | M | 57 | Methodist | German | Ontario | Farmers, general and nfs | 7 |
| 21 | ostrom | martha | F | 23 | Methodist | German | Ontario | No Occupation Listed | 100 |
| 5 | ostrom | mary | F | 45 | Methodist | Irish | Ontario | No Occupation Listed | 7 |
| 20 | ostrom | mary | F | 56 | Methodist | Scottish | Ontario | No Occupation Listed | 100 |
| 25 | ostrom | mary | F | 62 | Presbyterian | Dutch | Ontario | No Occupation Listed | 110 |
| 1 | ostrom | mary | F | 26 | Presbyterian | Dutch | Ontario | No Occupation Listed | 110 |
| 4 | ostrom | mary | F | 6 | Presbyterian | Dutch | United States | No Occupation Listed | 110 |
| 4 | ostrom | melissa | F | 28 | Methodist | English | Ontario | No Occupation Listed | 96 |
| 7 | ostrom | moira | F | 17 | Methodist | German | Ontario | No Occupation Listed | 7 |
| 10 | ostrom | walter | M | 2 | Methodist | German | Ontario | No Occupation Listed | 88 |
| 4 | osullivan | lilly | F | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 22 |
| 2 | osullivan | lizzie | F | 3 | Roman Catholic | Irish | United States | No Occupation Listed | 22 |
| 3 | osullivan | margaret | F | 2 | Roman Catholic | Irish | United States | No Occupation Listed | 22 |
| 1 | osullivan | mary | F | 25 | Roman Catholic | Irish | Ontario | No Occupation Listed | 22 |
| 6 | oswin | emma | F | 24 | Anglican | English | England | No Occupation Listed | 173 |
| 7 | oswin | george | M | 2 | Anglican | English | Ontario | No Occupation Listed | 173 |
| 5 | owens | catherine | F | 30 | Methodist | German | Ontario | No Occupation Listed | 62 |
| 4 | owens | william | M | 32 | Methodist | Irish | New York | Merchants, specified large-scale wholesaleing | 62 |