Residents of Oshawa, T-V — Sub-district E, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 25 | oconnell | cornelius | M | 18 | Roman Catholic | Irish | Ontario | Other furniture makers | 95 |
| 1 | oconnell | daniel | M | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 95 |
| 24 | oconnell | margaret | F | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 95 |
| 23 | oconnell | michal | M | 60 | Roman Catholic | Irish | Ireland | Labourers nfs | 95 |
| 6 | odea | elizabeth | F | 16 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 8 | odea | francis | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 9 | odea | frederick | M | 9 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 3 | odea | harriett | F | 42 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 2 | odea | james | M | 42 | Roman Catholic | Irish | Ireland | Others working in mines and quarries | 152 |
| 7 | odea | james | M | 14 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 5 | odea | margaret | F | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 152 |
| 4 | odea | william | M | 21 | Roman Catholic | Irish | Ontario | Upholsterers except vehicle | 152 |
| 24 | odell | h | M | 26 | Anglican | English | United States | Bookkeepers nfs | 232 |
| 23 | odriscoll | mary | F | 92 | Roman Catholic | Irish | Ireland | No Occupation Listed | 392 |
| 24 | odriscoll | michal | M | 26 | Roman Catholic | Irish | Ontario | Occupational title unclassifiable | 392 |
| 16 | okeefe | sarah | F | 60 | Roman Catholic | Irish | Ireland | No Occupation Listed | 295 |
| 15 | oregan | amanda | F | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 289 |
| 12 | oregan | ann | F | 50 | Roman Catholic | Irish | Ireland | No Occupation Listed | 289 |
| 11 | oregan | john | M | 75 | Roman Catholic | Irish | Ireland | Coopers etc. | 289 |
| 13 | oregan | john | M | 20 | Roman Catholic | Irish | Ontario | Coopers etc. | 289 |
| 16 | oregan | joseph | M | 13 | Roman Catholic | Irish | Ontario | No Occupation Listed | 289 |
| 14 | oregan | mary | F | 18 | Roman Catholic | Irish | Ontario | No Occupation Listed | 289 |
| 10 | oswald | jesse | F | 60 | Presbyterian | Scottish | Scotland | No Occupation Listed | 24 |