Residents of Madoc — Sub-district E, surnames O (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 3 | obrien | walter | M | 13 | Episcopal Methodist | Irish | Ontario | No Occupation Listed | 183 |
| 9 | obrine | william | M | 16 | Episcopal Methodist | Irish | Ontario | Servants nfs | 6 |
| 12 | oconnor | bridget | F | 25 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 2 | oconnor | bridget | F | 7 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 11 | oconnor | danial | M | 16 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 1 | oconnor | dennis | M | 9 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 6 | oconnor | domonid | M | 60 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 104 |
| 9 | oconnor | domonid | M | 26 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 104 |
| 15 | oconnor | domonid | M | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 21 | oconnor | edmond | M | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 24 | oconnor | elizabath | F | 13 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 18 | oconnor | ellin | F | 45 | Roman Catholic | Irish | Ireland | No Occupation Listed | 256 |
| 3 | oconnor | ellin | F | 5 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 5 | oconnor | fergus | M | 0 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 16 | oconnor | frank | M | 1 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 13 | oconnor | john | M | 9 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 4 | oconnor | john | M | 3 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 25 | oconnor | margret | F | 10 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 7 | oconnor | mary | F | 57 | Roman Catholic | Irish | Ireland | No Occupation Listed | 104 |
| 14 | oconnor | mary | F | 5 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 19 | oconnor | mary | F | 24 | Roman Catholic | Irish | Ontario | Milliners | 256 |
| 23 | oconnor | michael | M | 15 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 8 | oconnor | michal | M | 28 | Roman Catholic | Irish | Ontario | Labourers nfs | 104 |
| 17 | oconnor | michel | M | 53 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 256 |
| 22 | oconnor | rosann | F | 17 | Roman Catholic | Irish | Ontario | No Occupation Listed | 256 |
| 10 | oconnor | thomas | M | 19 | Roman Catholic | Irish | Ontario | No Occupation Listed | 104 |
| 20 | oconnor | william | M | 22 | Roman Catholic | Irish | Ontario | Farmers, general and nfs | 256 |
| 23 | oharra | charles | M | 45 | Episcopal Methodist | Irish | Ontario | Farmers, general and nfs | 219 |
| 21 | oharra | henrietta | F | 31 | Episcopal Methodist | French | Ontario | No Occupation Listed | 218 |
| 20 | oharra | henry | M | 34 | Episcopal Methodist | Irish | Ontario | Farmers, general and nfs | 218 |
| 25 | oharra | james | M | 83 | Episcopal Methodist | Irish | United States | No Occupation Listed | 219 |
| 24 | oharra | lucy | F | 44 | Episcopal Methodist | Irish | Ontario | No Occupation Listed | 219 |
| 22 | oharra | stanley | M | 0 | Episcopal Methodist | Irish | Ontario | No Occupation Listed | 218 |
| 4 | oharrah | alberta | F | 13 | Methodist | Irish | Ontario | No Occupation Listed | 189 |
| 19 | oharrah | benjamin | M | 27 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 213 |
| 25 | oharrah | benson | M | 32 | Methodist | Irish | Ontario | Dealer, merchant etc. (Wholesale & retail trade) | 189 |
| 2 | oharrah | frank | M | 22 | Methodist | Irish | Ontario | Farmers, general and nfs | 189 |
| 16 | oharrah | henry | M | 85 | Episcopal Methodist | Irish | United States | Farmers, general and nfs | 213 |
| 23 | oharrah | james | M | 53 | Methodist | Irish | Ontario | Farmers, general and nfs | 189 |
| 18 | oharrah | james | M | 30 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 213 |
| 1 | oharrah | lester | M | 30 | Methodist | Irish | Ontario | Farmers, general and nfs | 189 |
| 17 | oharrah | margret | F | 62 | Presbyterian | Irish | Ireland | No Occupation Listed | 213 |
| 24 | oharrah | mary | F | 53 | Methodist | English | Ontario | No Occupation Listed | 189 |
| 3 | oharrah | minna | F | 17 | Methodist | Irish | Ontario | No Occupation Listed | 189 |
| 20 | orrocik | adda | F | 2 | Roman Catholic | Irish | Ontario | No Occupation Listed | 149 |
| 17 | orrocik | bryn | M | 50 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 148 |
| 18 | orrocik | farrel | M | 45 | Roman Catholic | Irish | Ireland | Farmers, general and nfs | 149 |
| 21 | orrocik | jones | M | 8 | Roman Catholic | Irish | Ontario | No Occupation Listed | 149 |
| 19 | orrocik | sarah | F | 33 | Presbyterian | Welsh | Ontario | No Occupation Listed | 149 |
| 3 | osborn | drusilla | F | 25 | United Methodist/Bible Christian | English | Ontario | No Occupation Listed | 103 |
| 4 | osborn | rachel | F | 2 | United Methodist/Bible Christian | Irish | Ontario | No Occupation Listed | 103 |
| 5 | osborn | samual | M | 0 | United Methodist/Bible Christian | Irish | Ontario | No Occupation Listed | 103 |