Residents of Caledon — Sub-district D, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 7 | _oss | hector | M | 27 | Baptist | Scottish | Ontario | Labourers nfs | 126 |
| 23 | _own | agnes | F | 9 | Presbyterian | Scottish | Ontario | No Occupation Listed | 208 |
| 21 | _own | edward | M | 34 | Presbyterian | Scottish | Scotland | Spinners and winders | 208 |
| 24 | _own | jessy | F | 7 | Presbyterian | Scottish | Ontario | No Occupation Listed | 208 |
| 1 | _own | john | M | 2 | Presbyterian | Scottish | Ontario | No Occupation Listed | 208 |
| 22 | _own | mary | F | 34 | Presbyterian | Scottish | Scotland | No Occupation Listed | 208 |
| 25 | _own | mary | F | 4 | Presbyterian | Scottish | Ontario | No Occupation Listed | 208 |
| 4 | obrian | elizebeth | F | 63 | Roman Catholic | Irish | Ireland | No Occupation Listed | 122 |
| 6 | obrian | james | M | 25 | Roman Catholic | Irish | Ontario | No Occupation Listed | 122 |
| 5 | obrian | sarah | F | 28 | Roman Catholic | Irish | Ontario | No Occupation Listed | 122 |
| 6 | odonell | james | M | 35 | Roman Catholic | Irish | Ontario | Stone carvers or cutters and stone yard workers | 46 |
| 7 | ogston | elisabeth | F | 58 | Presbyterian | Scottish | Scotland | No Occupation Listed | 82 |
| 8 | ogston | robetson | M | 61 | Presbyterian | Scottish | Scotland | No Occupation Listed | 82 |
| 6 | ogston | thomas | M | 63 | Presbyterian | Scottish | Scotland | Mason nfs or combined | 82 |
| 24 | ohair | isabella | F | 3 | Anglican | Irish | Ontario | No Occupation Listed | 126 |
| 25 | ohair | mabell | F | 0 | Anglican | Irish | Ontario | No Occupation Listed | 126 |
| 23 | ohair | sharlet | F | 23 | Anglican | English | England | No Occupation Listed | 126 |
| 22 | ohair | thomas | M | 23 | Anglican | Irish | Ontario | Farmers, general and nfs | 126 |
| 14 | okeefe | larance | M | 49 | Roman Catholic | Irish | Ireland | Labourers nfs | 101 |
| 16 | okeefe | larance | M | 18 | Roman Catholic | Irish | Ireland | No Occupation Listed | 101 |
| 20 | okeefe | margret | F | 7 | Roman Catholic | Irish | Ontario | No Occupation Listed | 101 |
| 15 | okeefe | marry | F | 45 | Roman Catholic | Irish | Ireland | No Occupation Listed | 101 |
| 19 | okeefe | marry | F | 12 | Roman Catholic | Blank | Ireland | No Occupation Listed | 101 |
| 18 | okeefe | pattrick | M | 14 | Roman Catholic | Irish | Ireland | No Occupation Listed | 101 |
| 17 | okeefe | thomas | M | 16 | Roman Catholic | Irish | Ireland | No Occupation Listed | 101 |
| 1 | oleary | william | M | 19 | Roman Catholic | Irish | Ontario | Millers and related workers | 184 |
| 23 | oliver | ethel | F | 5 | Presbyterian | Scottish | Ontario | No Occupation Listed | 44 |
| 22 | oliver | jane | F | 29 | Presbyterian | Scottish | Ontario | No Occupation Listed | 44 |
| 17 | oliver | malcum | M | 28 | Presbyterian | Scottish | Ontario | Farmers, general and nfs | 43 |
| 18 | oliver | mary | F | 22 | Presbyterian | Scottish | Ontario | No Occupation Listed | 43 |
| 15 | oliver | robert | M | 65 | Presbyterian | Scottish | Scotland | Farmers, general and nfs | 43 |
| 16 | oliver | sarah | F | 62 | Presbyterian | Scottish | Scotland | No Occupation Listed | 43 |
| 20 | oliver | sarah | F | 17 | Presbyterian | Scottish | Ontario | No Occupation Listed | 43 |
| 21 | oliver | thomas | M | 32 | Presbyterian | Scottish | Ontario | Sawyer, and other titled wood or sawmill operatives | 44 |
| 19 | oliver | william | M | 20 | Presbyterian | Scottish | Ontario | Farmers, general and nfs | 43 |
| 3 | orhander | w | M | 28 | Methodist | English | Ontario | Farmers, general and nfs | 56 |
| 1 | ostrander | abraham | M | 55 | Methodist | German | Ontario | Farmers, general and nfs | 153 |
| 6 | ostrander | florance | F | 6 | Methodist | German | Ontario | No Occupation Listed | 153 |
| 3 | ostrander | lawrance | M | 12 | Methodist | German | Ontario | No Occupation Listed | 153 |
| 8 | ostrander | loezea | F | 1 | Methodist | German | Ontario | No Occupation Listed | 153 |
| 7 | ostrander | margaret | F | 4 | Methodist | German | Ontario | No Occupation Listed | 153 |
| 2 | ostrander | moria | F | 43 | Methodist | English | Ontario | No Occupation Listed | 153 |
| 4 | ostrander | sarah | F | 10 | Methodist | German | Ontario | No Occupation Listed | 153 |
| 5 | ostrander | wentworth | M | 8 | Methodist | German | Ontario | No Occupation Listed | 153 |
| 21 | overland | charles | M | 33 | Anglican | English | Ontario | Farmers, general and nfs | 112 |
| 25 | overland | deborah | F | 25 | Presbyterian | English | Ontario | No Occupation Listed | 113 |
| 22 | overland | ellen | F | 23 | Presbyterian | Irish | Ontario | No Occupation Listed | 112 |
| 23 | overland | margaret | F | 1 | Presbyterian | English | Ontario | No Occupation Listed | 112 |
| 3 | overland | martha | F | 2 | Presbyterian | English | Ontario | No Occupation Listed | 113 |
| 2 | overland | mary | F | 4 | Presbyterian | English | Ontario | No Occupation Listed | 113 |
| 24 | overland | richard | M | 26 | Presbyterian | English | Ontario | Farmers, general and nfs | 113 |
| 1 | overland | richard | M | 6 | Presbyterian | English | Ontario | No Occupation Listed | 113 |