Residents of Chatham, Town—Ville — Sub-district I, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 3 | o...er | hattie | F | 18 | Methodist | Blank | Ontario | No Occupation Listed | 256 |
| 12 | obrien | anna | F | 14 | Anglican | Irish | Ireland | No Occupation Listed | 281 |
| 13 | obrien | ed | M | 12 | Anglican | Irish | England | No Occupation Listed | 281 |
| 11 | obrien | emily | F | 17 | Anglican | Irish | England | No Occupation Listed | 281 |
| 10 | obrien | m | F | 43 | Anglican | Irish | Ireland | No Occupation Listed | 281 |
| 9 | oflynn | ellen | F | 62 | Roman Catholic | Irish | Ireland | No Occupation Listed | 23 |
| 11 | oflynn | john | M | 24 | Roman Catholic | Irish | Ontario | lawyer | 23 |
| 10 | oflynn | julia | F | 32 | Roman Catholic | Irish | Ontario | No Occupation Listed | 23 |
| 8 | oflynn | patrick | M | 75 | Roman Catholic | Irish | Ireland | Coopers etc. | 23 |
| 20 | ogan | edward | M | 30 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 261 |
| 22 | ogle | flora | F | 27 | Methodist | English | England | No Occupation Listed | 220 |
| 23 | ogle | george | M | 4 | Methodist | Irish | Ontario | No Occupation Listed | 220 |
| 21 | ogle | john | M | 35 | Methodist | Irish | Ontario | Boot and shoemakers and repairers | 220 |
| 22 | ohara | ellen | F | 2 | Anglican | English | Ontario | No Occupation Listed | 369 |
| 20 | ohara | francis | M | 10 | Anglican | English | Ontario | No Occupation Listed | 369 |
| 18 | ohara | maria | F | 31 | Anglican | Irish | Ireland | No Occupation Listed | 369 |
| 21 | ohara | murrey | M | 5 | Anglican | English | Ontario | No Occupation Listed | 369 |
| 17 | ohara | robert | M | 55 | Anglican | English | England | Legislative officials and heads of government | 369 |
| 19 | ohara | walter | M | 12 | Anglican | English | Ontario | No Occupation Listed | 369 |
| 12 | ohare | susan | F | 25 | Roman Catholic | Irish | United States | No Occupation Listed | 782 |
| 1 | oheir | margaret | F | 64 | Roman Catholic | Irish | Ireland | No Occupation Listed | 409 |
| 2 | oheir | margaret | F | 9 | Roman Catholic | Irish | United States | No Occupation Listed | 409 |
| 14 | okeefe | catherine | F | 45 | Roman Catholic | Irish | Ireland | No Occupation Listed | 193 |
| 13 | okeefe | dennis | M | 49 | Roman Catholic | Irish | Ireland | Boot and shoemakers and repairers | 193 |
| 17 | okeefe | heney | M | 9 | Roman Catholic | Irish | Ontario | No Occupation Listed | 193 |
| 16 | okeefe | homorah | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 193 |
| 15 | okeefe | joseph | M | 14 | Roman Catholic | Irish | Ontario | No Occupation Listed | 193 |
| 1 | old | harry | M | 20 | | Blank | Ontario | Bartenders | 362 |
| 6 | oldershaw | alfred | M | 32 | Methodist | English | Ontario | Mason nfs or combined | 308 |
| 8 | oldershaw | ann | F | 22 | Methodist | English | Ontario | No Occupation Listed | 2 |
| 18 | oldershaw | arthur | M | 2 | Baptist | Blank | Ontario | No Occupation Listed | 413 |
| 15 | oldershaw | edith | F | 5 | Methodist | English | Ontario | No Occupation Listed | 278 |
| 10 | oldershaw | emma | F | 18 | Methodist | English | Ontario | No Occupation Listed | 2 |
| 17 | oldershaw | francis | F | 23 | Baptist | Blank | Ontario | No Occupation Listed | 413 |
| 11 | oldershaw | frank | M | 16 | Methodist | English | Ontario | No Occupation Listed | 2 |
| 12 | oldershaw | grace | F | 13 | Methodist | English | Ontario | No Occupation Listed | 2 |
| 13 | oldershaw | isabella | F | 59 | Methodist | English | England | No Occupation Listed | 2 |
| 13 | oldershaw | james | M | 39 | Methodist | Blank | Ontario | Bricklayers | 447 |
| 9 | oldershaw | joseph | M | 21 | Methodist | English | Ontario | Blacksmiths | 2 |
| 9 | oldershaw | myrtle | F | 0 | | English | Ontario | No Occupation Listed | 308 |
| 8 | oldershaw | roy | M | 3 | | English | Ontario | No Occupation Listed | 308 |
| 14 | oldershaw | sarah | F | 26 | Methodist | Blank | Ontario | No Occupation Listed | 447 |
| 14 | oldershaw | sarah | F | 26 | Methodist | English | United States | No Occupation Listed | 278 |
| 7 | oldershaw | selina | F | 31 | Methodist | English | England | No Occupation Listed | 308 |
| 13 | oldershaw | walter | M | 33 | Methodist | English | Ontario | Mason nfs or combined | 278 |
| 16 | oldershaw | william | M | 28 | Baptist | Blank | Ontario | Tinsmiths and Tinners and Tinkers | 413 |
| 7 | oldershaw | wm | M | 58 | Methodist | English | England | Mason nfs or combined | 2 |
| 13 | oleary | alice | F | 46 | Roman Catholic | Irish | Ireland | No Occupation Listed | 489 |
| 15 | oleary | alice | F | 20 | Roman Catholic | Irish | Ontario | No Occupation Listed | 489 |
| 12 | oleary | john | M | 65 | Roman Catholic | Irish | Ireland | Teachers (unspecified) | 489 |
| 17 | oleary | john | M | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 489 |
| 18 | oleary | sophia | F | 12 | Roman Catholic | Irish | Ontario | No Occupation Listed | 489 |
| 16 | oleary | terese | F | 16 | Roman Catholic | Irish | Ontario | No Occupation Listed | 489 |
| 14 | oleary | thomas | M | 26 | Roman Catholic | Irish | Ontario | No Occupation Listed | 489 |
| 24 | oliver | eliza | F | 12 | Baptist | English | England | No Occupation Listed | 655 |
| 20 | oliver | elizabeth | F | 42 | Baptist | English | England | No Occupation Listed | 655 |
| 22 | oliver | george | M | 16 | Baptist | English | England | No Occupation Listed | 655 |
| 25 | oliver | hannah | F | 23 | Baptist | Blank | Ontario | No Occupation Listed | 346 |
| 21 | oliver | ida | F | 18 | Baptist | English | England | No Occupation Listed | 655 |
| 23 | oliver | mary | F | 14 | Baptist | English | England | No Occupation Listed | 655 |
| 1 | oliver | maud | F | 0 | Baptist | English | Ontario | No Occupation Listed | 346 |
| 24 | oliver | william | M | 24 | Baptist | English | Ontario | Machinists | 346 |
| 19 | oliver | wm | M | 46 | Baptist | English | England | Labourers nfs | 655 |
| 20 | oneil | c | M | 33 | Roman Catholic | Irish | Ontario | barrister | 357 |
| 21 | oneil | james | M | 31 | Roman Catholic | Irish | Ontario | No Occupation Listed | 357 |
| 22 | oneil | jane | F | 29 | Roman Catholic | Irish | Ontario | No Occupation Listed | 357 |
| 25 | oneil | margaret | F | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 357 |
| 23 | oneil | mary | F | 27 | Roman Catholic | Irish | Ontario | No Occupation Listed | 357 |
| 24 | oneil | robet | M | 22 | Roman Catholic | Irish | Ontario | No Occupation Listed | 357 |
| 6 | oneill | essie | F | 27 | Anglican | Irish | Ireland | No Occupation Listed | 396 |
| 5 | oneill | j | M | 34 | Anglican | Irish | Ireland | Clerk, nfs | 396 |
| 7 | oneill | jennie | F | 3 | Anglican | Irish | Ontario | No Occupation Listed | 396 |
| 8 | oneill | john | M | 0 | Anglican | Irish | Ontario | No Occupation Listed | 396 |
| 6 | oriley | ellen | F | 23 | Roman Catholic | Irish | Ireland | No Occupation Listed | 185 |
| 5 | oriley | peter | M | 24 | Roman Catholic | Irish | Quebec | Boot and shoemakers and repairers | 185 |
| 7 | oriley | william | M | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 185 |
| 4 | oriork | albert | M | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 290 |
| 3 | oriork | john | M | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 290 |
| 2 | oriork | margaret | F | 25 | Roman Catholic | Irish | Ontario | No Occupation Listed | 290 |
| 1 | oriork | patrick | M | 37 | Roman Catholic | Irish | Ontario | Labourers nfs | 290 |
| 18 | orr | anna | F | 21 | Methodist | English | Ontario | No Occupation Listed | 436 |
| 19 | orr | georgiana | F | 17 | Methodist | English | Ontario | No Occupation Listed | 436 |
| 15 | orr | jane | F | 50 | Methodist | English | Ontario | No Occupation Listed | 436 |
| 16 | orr | jane | F | 27 | Methodist | English | Ontario | No Occupation Listed | 436 |
| 17 | orr | mary | F | 24 | Methodist | English | Ontario | No Occupation Listed | 436 |
| 19 | osong | charles | M | 15 | Methodist | African Origins | Ontario | No Occupation Listed | 118 |
| 20 | osong | elizabeth | F | 13 | Methodist | African Origins | Ontario | No Occupation Listed | 118 |
| 18 | osong | harriet | F | 35 | Methodist | English | England | No Occupation Listed | 118 |
| 21 | osong | isabella | F | 11 | Methodist | African Origins | Ontario | No Occupation Listed | 118 |
| 23 | osong | sarah | F | 1 | Methodist | African Origins | Ontario | No Occupation Listed | 118 |
| 17 | osong | william | M | 42 | Methodist | African Origins | Ontario | Labourers nfs | 118 |
| 22 | osong | william | M | 9 | Methodist | African Origins | Ontario | No Occupation Listed | 118 |
| 18 | ott | annie | F | 6 | Roman Catholic | German | Ontario | No Occupation Listed | 282 |
| 17 | ott | charles | M | 9 | Roman Catholic | German | Ontario | No Occupation Listed | 282 |
| 14 | ott | jane | F | 38 | Roman Catholic | Irish | Ontario | No Occupation Listed | 282 |
| 16 | ott | jennie | F | 13 | Roman Catholic | German | Ontario | No Occupation Listed | 282 |
| 13 | ott | john | M | 43 | Roman Catholic | German | Germany | Labourers nfs | 282 |
| 20 | ott | john | M | 0 | Roman Catholic | German | Ontario | No Occupation Listed | 282 |
| 15 | ott | margaret | F | 15 | Roman Catholic | German | Ontario | No Occupation Listed | 282 |
| 19 | ott | ursuline | F | 3 | Roman Catholic | German | Ontario | No Occupation Listed | 282 |
| 2 | ouellette | emma | F | 15 | | French | Ontario | No Occupation Listed | 103 |
| 3 | ouellette | julia | F | 9 | | French | Ontario | No Occupation Listed | 103 |
| 22 | ouillette | bridget | F | 35 | Roman Catholic | Irish | Ontario | No Occupation Listed | 92 |
| 21 | ouillette | urtal | M | 40 | Roman Catholic | French | Ontario | Blacksmiths | 92 |
| 10 | overton | george | M | 31 | Anglican | English | England | Labourers nfs | 299 |
| 11 | overton | margaret | F | 29 | Roman Catholic | French | Quebec | No Occupation Listed | 299 |
| 7 | owens | albert | M | 6 | Primitive Methodist | Irish | Ontario | No Occupation Listed | 363 |
| 8 | owens | geo | M | 1 | Primitive Methodist | Irish | Ontario | No Occupation Listed | 363 |
| 5 | owens | hannah | F | 36 | Primitive Methodist | American | Ontario | No Occupation Listed | 363 |
| 4 | owens | james | M | 43 | Primitive Methodist | Irish | Ontario | Labourers nfs | 363 |
| 6 | owens | wm | M | 15 | Primitive Methodist | Irish | Ontario | No Occupation Listed | 363 |
| 3 | oxenden | ann | F | 42 | Methodist | African Origins | United States | No Occupation Listed | 743 |
| 4 | oxenden | chas | M | 12 | Methodist | African Origins | Ontario | No Occupation Listed | 743 |
| 2 | oxenden | danl | M | 67 | Methodist | African Origins | United States | Labourers nfs | 743 |
| 6 | oxenden | james | M | 8 | Methodist | African Origins | Ontario | No Occupation Listed | 743 |
| 5 | oxenden | susan | F | 10 | Methodist | African Origins | Ontario | No Occupation Listed | 743 |
| 8 | oxenden | thomas | M | 1 | Methodist | African Origins | Ontario | No Occupation Listed | 743 |
| 7 | oxenden | wm | M | 5 | Methodist | African Origins | Ontario | No Occupation Listed | 743 |
| 5 | oxidiul | amelia | F | 40 | Methodist | African Origins | Kentucky | No Occupation Listed | 134 |
| 8 | oxidiul | bruce | M | 4 | Methodist | African Origins | Kentucky | No Occupation Listed | 134 |
| 9 | oxidiul | charles | M | 12 | Methodist | African Origins | Kentucky | No Occupation Listed | 134 |
| 4 | oxidiul | daniel | M | 60 | Methodist | African Origins | Kentucky | Labourers nfs | 134 |
| 6 | oxidiul | james | M | 6 | Methodist | African Origins | Kentucky | No Occupation Listed | 134 |
| 7 | oxidiul | susan | F | 10 | Methodist | African Origins | Kentucky | No Occupation Listed | 134 |
| 10 | oxidiul | thomas | M | 0 | Methodist | African Origins | Kentucky | No Occupation Listed | 134 |
| 10 | ozard | alice | F | 14 | Anglican | English | England | No Occupation Listed | 473 |
| 23 | ozard | elizabeth | F | 30 | Anglican | English | England | No Occupation Listed | 471 |
| 25 | ozard | margaret | F | 4 | Anglican | English | Ontario | No Occupation Listed | 471 |
| 12 | ozard | margaret | F | 8 | Anglican | English | England | No Occupation Listed | 473 |
| 9 | ozard | peter | M | 42 | Anglican | English | England | Blacksmiths | 473 |
| 11 | ozard | peter | M | 10 | Anglican | English | England | No Occupation Listed | 473 |
| 2 | ozard | robert | M | 23 | Anglican | English | England | Blacksmiths | 471 |
| 1 | ozard | walter | M | 2 | Anglican | English | Ontario | No Occupation Listed | 471 |
| 22 | ozard | william | M | 38 | Anglican | English | England | Blacksmiths | 471 |
| 24 | ozard | william | M | 6 | Anglican | English | Ontario | No Occupation Listed | 471 |