1841 Census - surnames beginning with O
| Last Name | First Name | Age | Parish | Piece | Folio | Page |
| O'BEIRNE | Ada | 15 | Lezayre | 1464/1 | 6 | 5 |
| O'BEIRNE | Louisa | 55 | Lezayre | 1464/1 | 6 | 5 |
| O'BEIRNE | Louisa | 40 | Lezayre | 1464/1 | 6 | 5 |
| O'HARA | Catherine | 9 | Douglas | 1465/8 | 33 | 23 |
| O'HARA | John | 11 | Douglas | 1465/8 | 33 | 23 |
| O'HARA | Margaret | 37 | Douglas | 1465/8 | 32 | 22 |
| O'HARA | Robert | 52 | Douglas | 1465/8 | 32 | 22 |
| O'HARA | Robert | 4 | Douglas | 1465/8 | 33 | 23 |
| O'HARA | William | 16 | Douglas | 1465/8 | 33 | 23 |
| O'HARE | Ann | 25 | Peel | 1463/8 | 8 | 10 |
| O'HARE | Catherine | 20 | Rushen | 1465/11 | 30 | 26 |
| O'KEAFFLEY | Ann | 36 | Douglas | 1465/3 | 26 | 28 |
| O'KELLY | James | 20 | Douglas | 1465/4 | 31 | 9 |
| O'NAIL | Ann | 20 | Marown | 1464/6 | 29 | 3 |
| O'NEILL | Anne | 16 | Arbory | 1463/3 | 15 | 24 |
| O'NEIL | Catherine | 50 | Douglas | 1465/4 | 18 | 29 |
| O'NEIL | James | 50 | Douglas | 1465/4 | 18 | 29 |
| O'NEILL | Sarah | 40 | Arbory | 1463/3 | 15 | 24 |
| O'REILLY | Ellinor | 15 | Onchan | 1465/1 | 26 | 12 |
| O'REILLY | John | 23 | Onchan | 1465/1 | 26 | 12 |
| O'REILLY | Maryanne | 25 | Onchan | 1465/1 | 26 | 12 |
| O'REILLY | Susannah | 55 | Onchan | 1465/1 | 26 | 12 |
| O'REILLY | Thomas | 21 | Onchan | 1465/1 | 26 | 12 |
| O'SULLIVAN | Charlotte | 32 | Douglas | 1465/5 | 26 | 48 |
| O'SULLIVAN | James | 30 | Douglas | 1465/5 | 26 | 48 |
| OATS | Ann | 50 | Douglas | 1465/7 | 18 | 31 |
| OATES | Ann | 50 | Douglas | 1465/8 | 13 | 22 |
| OATES | Ann | 50 | Peel | 1463/8 | 38 | 3 |
| OATES | Ann | 45 | Onchan | 1465/2 | 20 | 16 |
| OATES | Ann | 35 | Michael | 1464/9 | 18 | 3 |
| OATES | Ann | 15 | Douglas | 1465/3 | 30 | 35 |
| OATES | Anne | 1 | Braddan | 1463/5 | 11 | 16 |
| OATES | Catherine | 70 | Braddan | 1463/5 | 30 | 21 |
| OATES | Catherine | 40 | Douglas | 1465/3 | 29 | 34 |
| OATES | Catrin | 35 | German | 1463/7 | 32 | 8 |
| OATES | Catherine | 35 | Santon | 1463/2 | 26 | 10 |
| OATES | Catherine | 20 | Braddan | 1463/5 | 30 | 21 |
| OATES | Catherine | 3 mos | Braddan | 1463/5 | 30 | 21 |
| OATES | Catherine | 4 mos | Santon | 1463/2 | 26 | 10 |
| OATES | Christian | 50 | Peel | 1463/8 | 38 | 3 |
| OATS | Christian | 14 | Douglas | 1465/7 | 18 | 31 |
| OATES | Edward | 80 | Braddan | 1463/5 | 30 | 21 |
| OATES | Edward | 45 | Onchan | 1465/2 | 20 | 16 |
| OATES | Edward Jnr | 30 | Braddan | 1463/5 | 30 | 21 |
| OATES | Edward | 15 | Onchan | 1465/2 | 20 | 16 |
| OATES | Edward | 5 | Braddan | 1463/5 | 30 | 21 |
| OATES | Eleanor | 25 | Andreas | 1463/1 | 77 | 10 |
| OATES | Eleanor | 20 | Santon | 1463/2 | 6 | 5 |
| OATS | Eleanor | 15 | Marown | 1464/6 | 20 | 9 |
| OATES | Eleanor | 15 | Michael | 1464/9 | 18 | 3 |
| OATES | Eleanor | 12 | Onchan | 1465/1 | 5 | 3 |
| OATES | Elizabeth | 50 | Onchan | 1465/1 | 4 | 2 |
| OATES | Elizabeth | 32 | Douglas | 1465/5 | 27 | 49 |
| OATES | Elizabeth | 26 | Michael | 1464/9 | 18 | 3 |
| OATS | Elizabeth | 22 | Douglas | 1465/7 | 18 | 32 |
| OATES | Elizabeth | 15 | Douglas | 1465/5 | 13 | 22 |
| OATES | Elizabeth | 11 | Onchan | 1465/2 | 20 | 16 |
| OATS | Eliza | 10 | Ballaugh | 1463/4 | 29 | 8 |
| OATES | Esther | 5 | Andreas | 1463/1 | 77 | 10 |
| OATES | Fred | 15 | Douglas | 1465/3 | 18 | 12 |
| OATS | Frederick | 4 | Peel | 1463/8 | 29 | 15 |
| OATES | Henry | 2 | Santon | 1463/2 | 26 | 10 |
| OATES | Isabella | 25 | Lezayre | 1464/1 | 68 | 9 |
| OATES | James | 80 | Michael | 1464/9 | 18 | 3 |
| OATES | James | 28 | Douglas | 1465/8 | 29 | 16 |
| OATS | James | 25 | Malew | 1464/3 | 34 | 4 |
| OATES | James | 20 | Onchan | 1465/2 | 9 | 11 |
| OATS | James | 15 | Santon | 1463/2 | 6 | 6 |
| OATS | James | 12 | Ballaugh | 1463/4 | 29 | 8 |
| OATES | James | 10 | Santon | 1463/2 | 26 | 10 |
| OATES | Jane | 60 | Santon | 1463/2 | 6 | 5 |
| OATES | Jane | 40 | Douglas | 1465/6 | 14 | 23 |
| OATES | Jane | 40 | Michael | 1464/9 | 18 | 3 |
| OATES | Jane | 25 | Douglas | 1465/5 | 13 | 22 |
| OATES | Jane | 22 | Onchan | 1465/1 | 32 | 24 |
| OATES | Jane | 15 | Santon | 1463/2 | 26 | 10 |
| OATES | Jane | 7 | Michael | 1464/9 | 18 | 3 |
| OATES | John | 80 | Onchan | 1465/2 | 9 | 11 |
| OATES | John | 65 | Onchan | 1465/1 | 4 | 2 |
| OATES | John | 50 | Michael | 1464/9 | 18 | 3 |
| OATES | John | 30 | Andreas | 1463/1 | 77 | 10 |
| OATS | John | 30 | Onchan | 1465/2 | 13 | 1 |
| OATES | John | 14 | Onchan | 1465/1 | 28 | 15 |
| OATES | John | 9 | Onchan | 1465/2 | 20 | 16 |
| OATES | John | 3 | Andreas | 1463/1 | 77 | 10 |
| OATES | John | 4 mos | German | 1463/7 | 32 | 8 |
| OATS | Joseph | 9 | Douglas | 1465/7 | 18 | 31 |
| OATS | Margaret | 60 | Onchan | 1465/2 | 13 | 1 |
| OATES | Margaret | 59 | Onchan | 1465/1 | 4 | 2 |
| OATES | Margaret | 50 | Lezayre | 1464/1 | 34 | 7 |
| OATES | Margaret | 14 | Lezayre | 1464/1 | 34 | 7 |
| OATES | Margaret | 10 | German | 1463/7 | 32 | 8 |
| OATES | Margaret | 9 | Michael | 1464/9 | 18 | 3 |
| OATES | Margaret | 6 | German | 1463/7 | 31 | 6 |
| OATES | Margaret | 3 | Braddan | 1463/5 | 30 | 21 |
| OATS | Martha | 6 | Ballaugh | 1463/4 | 29 | 8 |
| OATES | Mary | 70 | Michael | 1464/9 | 18 | 3 |
| OATES | Mary | 65 | Onchan | 1465/2 | 9 | 11 |
| OATES | Mary | 53 | Douglas | 1465/3 | 18 | 12 |
| OATS | Mary | 40 | Ballaugh | 1463/4 | 29 | 8 |
| OATES | Mary | 26 | Douglas | 1465/8 | 29 | 16 |
| OATS | Mary | 25 | Peel | 1463/8 | 29 | 15 |
| OATS | Mary | 19 | Douglas | 1465/7 | 18 | 32 |
| OATES | Mary | 15 | Onchan | 1465/1 | 31 | 21 |
| OATES | Mary Ann | 13 | Onchan | 1465/2 | 20 | 16 |
| OATES | Michael | 50 | Peel | 1463/8 | 38 | 3 |
| OATES | Robert | 68 | Douglas | 1465/3 | 18 | 12 |
| OATS | Robert | 60 | Onchan | 1465/2 | 13 | 1 |
| OATES | Robert | 45 | Lezayre | 1464/1 | 34 | 7 |
| OATES | Robert | 25 | Michael | 1464/9 | 18 | 3 |
| OATS | Robert | 7 | Ballaugh | 1463/4 | 29 | 8 |
| OATS | Thomas | 55 | Douglas | 1465/7 | 18 | 31 |
| OATES | Thomas | 55 | Santon | 1463/2 | 26 | 10 |
| OATES | Thomas | 35 | German | 1463/7 | 32 | 8 |
| OATES | Thomas | 34 | Michael | 1464/9 | 18 | 3 |
| OATES | Thomas | 20 | Santon | 1463/2 | 13 | 2 |
| OATES | Thomas | 18 | Onchan | 1465/1 | 5 | 3 |
| OATES | Thomas | 13 | German | 1463/7 | 32 | 8 |
| OATES | William | 60 | Santon | 1463/2 | 6 | 5 |
| OATS | William | 42 | Ballaugh | 1463/4 | 29 | 8 |
| OATES | William | 40 | Lezayre | 1464/1 | 68 | 9 |
| OATES | William | 40 | Michael | 1464/9 | 18 | 3 |
| OATES | William | 25 | Santon | 1463/2 | 8 | 9 |
| OATES | William | 15 | Onchan | 1465/1 | 5 | 3 |
| OATES | William | 15 | Santon | 1463/2 | 26 | 10 |
| OATES | William | 10 | Onchan | 1465/2 | 20 | 16 |
| OATS | William | 3 | Lonan | 1464/2 | 41 | 18 |
| OATES | William | 1 | Andreas | 1463/1 | 77 | 10 |
| OBERTON | Thomas | 45 | Douglas | 1465/8 | 6 | 8 |
| OGILVIE | Sophia | 45 | Douglas | 1465/3 | 6 | 5 |
| OLAVENT | Ammea | 40 | Braddan | 1463/5 | 5 | 3 |
| OLIVER | Alexander | 40 | Castletown | 1464/5 | 41 | 1 |
| OLIVER | Ann | 20 | Lonan | 1464/2 | 57 | 24 |
| OLIVER | James | 25 | Lonan | 1464/2 | 57 | 24 |
| OLIVER | John | 20 | Douglas | 1465/3 | 15 | 5 |
| OLIVER | John | 2 | Lonan | 1464/2 | 57 | 24 |
| OLIVER | Mary | 1 | Castletown | 1464/5 | 41 | 1 |
| OLIVER | Sarah | 39 | Castletown | 1464/5 | 41 | 1 |
| OLIVER | Sarah | 4 | Castletown | 1464/5 | 41 | 1 |
| OLIVER | Thomas | 2 mos | Lonan | 1464/2 | 57 | 24 |
| OMAN | Ann | 40 | Douglas | 1465/8 | 7 | 9 |
| OMAN | Isabella Jane | 3 | Douglas | 1465/8 | 7 | 10 |
| OMAN | Mary Ann | 5 | Douglas | 1465/8 | 7 | 10 |
| OMEROD | Edgar | 3 | Douglas | 1465/8 | 5 | 5 |
| OMEROD | Elizabeth | 17 | Douglas | 1465/8 | 4 | 4 |
| OMEROD | George | 6 | Douglas | 1465/8 | 5 | 5 |
| OMEROD | Joseph | 10 | Douglas | 1465/8 | 5 | 5 |
| OMEROD | Mary | 39 | Douglas | 1465/8 | 4 | 4 |
| OMEROD | Mary | 12 | Douglas | 1465/8 | 5 | 5 |
| OMEROD | Peter | 41 | Douglas | 1465/8 | 4 | 4 |
| OMEROD | Sarah | 18 | Douglas | 1465/8 | 4 | 4 |
| OMEROD | Thomas | 5 | Douglas | 1465/8 | 5 | 5 |
| OMEROD | William | 15 | Douglas | 1465/8 | 5 | 5 |
| OPENSHAW | Edwin | 50 | Douglas | 1465/4 | 30 | 7 |
| OPENSHAW | Edwin | 5 | Douglas | 1465/4 | 30 | 7 |
| OPENSHAW | Honor | 40 | Douglas | 1465/4 | 30 | 7 |
| OPENSHAW | Susan | 20 | Douglas | 1465/4 | 30 | 7 |
| ORE | John | 6 mos | Lezayre | 1464/1 | 45 | 10 |
| ORR | Thomas | 70 | Ramsey | 1464/8 | 45 | 22 |
| ORSH | James | 14 | Lonan | 1464/2 | 54 | 18 |
| OSWALD | Esther | 20 | Douglas | 1465/3 | 18 | 12 |
| OSWALD | Francis | 11 | Douglas | 1465/3 | 25 | 25 |
| OSWALD | Henry | 50 | Douglas | 1465/3 | 25 | 25 |
| OSWALD | Henry | 14 | Douglas | 1465/3 | 25 | 25 |
| OSWALD | Joseph | 3 | Douglas | 1465/3 | 25 | 25 |
| OSWALD | Sarah | 40 | Douglas | 1465/3 | 25 | 25 |
| OSWALD | Sarah | 10 | Douglas | 1465/3 | 25 | 25 |
| OSWALD | William | 1 | Douglas | 1465/3 | 25 | 25 |
| OVERLY | James | 10 | Douglas | 1465/8 | 25 | 7 |
| OWEN | Arthur | 5 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Caroline | 40 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Caroline | 15 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Edward | 2 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Elizabeth | 25 | Douglas | 1465/3 | 23 | 22 |
| OWEN | Emma | 14 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Harriet | 9 mos | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Isabel | 4 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Thomas | 50 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | Thomas | 12 | Ramsey | 1464/8 | 57 | 13 |
| OWEN | William | 7 | Ramsey | 1464/8 | 57 | 13 |
| OWENS | Henry | 30 | Douglas | 1465/5 | 21 | 37 |
| OWENS | Jane | 36 | Douglas | 1465/7 | 19 | 33 |
| OWENS | John | 36 | Douglas | 1465/7 | 19 | 33 |
| OWENS | Sarah | 30 | Douglas | 1465/5 | 21 | 37 |