Residents of Petrolia, T-V — Sub-district F, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 21 | odbert | james | M | 32 | Anglican | Irish | Quebec | Carpenters | 221 |
| 22 | odbert | mary | F | 26 | Anglican | English | Ontario | No Occupation Listed | 221 |
| 5 | odell | austin | M | 13 | Baptist | American | United States | No Occupation Listed | 234 |
| 1 | odell | charles | M | 14 | Wesleyan Methodist | English | England | No Occupation Listed | 344 |
| 24 | odell | ebenezer | M | 21 | Wesleyan Methodist | English | England | Labourers nfs | 344 |
| 4 | odell | edwin | M | 28 | Baptist | English | England | Labourers nfs | 190 |
| 21 | odell | elizabeth | F | 53 | Wesleyan Methodist | English | England | No Occupation Listed | 344 |
| 22 | odell | fredrick | M | 30 | Wesleyan Methodist | English | England | Labourers nfs | 344 |
| 4 | odell | harriet | F | 47 | Baptist | American | United States | Seamstress | 234 |
| 25 | odell | james | M | 18 | Wesleyan Methodist | English | England | Labourers nfs | 344 |
| 2 | odell | lizzie | F | 16 | Wesleyan Methodist | English | England | No Occupation Listed | 344 |
| 3 | odell | mary | F | 11 | Wesleyan Methodist | English | Ontario | No Occupation Listed | 344 |
| 5 | odell | mary | F | 76 | Baptist | English | England | No Occupation Listed | 344 |
| 7 | odell | orville | M | 11 | Baptist | American | United States | No Occupation Listed | 234 |
| 6 | odell | patience | F | 12 | Baptist | American | United States | No Occupation Listed | 234 |
| 5 | odell | rachel | F | 26 | Baptist | English | Ontario | No Occupation Listed | 190 |
| 23 | odell | samuel | M | 24 | Wesleyan Methodist | English | England | Labourers nfs | 344 |
| 6 | odell | william | M | 0 | Baptist | English | Ontario | No Occupation Listed | 190 |
| 20 | odell | william | M | 52 | Wesleyan Methodist | English | England | Labourers nfs | 344 |
| 4 | odell | zophar | F | 8 | Wesleyan Methodist | English | Ontario | No Occupation Listed | 344 |
| 5 | oliver | winfred | F | 26 | Anglican | English | Ontario | No Occupation Listed | 233 |
| 23 | oneil | ellen | F | 23 | Roman Catholic | Irish | United States | Servants nfs | 125 |
| 8 | oneil | louise | F | 19 | Presbyterian | Irish | Ontario | No Occupation Listed | 210 |
| 3 | oneil | mary | F | 27 | Anglican | Irish | Ontario | Milliners | 293 |
| 2 | orchard | charles | M | 13 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 243 |
| 3 | orchard | emiline | F | 11 | Episcopal Methodist | Scottish | Ontario | No Occupation Listed | 243 |
| 13 | oreilly | elizabeth | F | 55 | Roman Catholic | Irish | Ireland | No Occupation Listed | 39 |
| 12 | oreilly | lawarence | M | 40 | Roman Catholic | Irish | Ireland | Labourers nfs | 39 |
| 20 | osborne | alice | F | 6 | Anglican | English | Ontario | No Occupation Listed | 80 |
| 22 | osborne | debbie | F | 3 | Anglican | Irish | Ontario | No Occupation Listed | 157 |
| 19 | osborne | erma | F | 26 | Anglican | Irish | United States | No Occupation Listed | 157 |
| 21 | osborne | florence | F | 5 | Anglican | Irish | Ontario | No Occupation Listed | 157 |
| 19 | osborne | henry | M | 10 | Anglican | English | Ontario | No Occupation Listed | 80 |
| 20 | osborne | ida | F | 8 | Anglican | Irish | Ontario | No Occupation Listed | 157 |
| 21 | owen | annie | F | 12 | Methodist | American | Ontario | No Occupation Listed | 13 |
| 13 | owens | john | M | 9 | Methodist | Irish | United States | No Occupation Listed | 161 |