1851 Census - surnames beginning with O
| Last Name | First Name | Age | Parish | Piece | Folio | Page |
| O'BENNETT | Bryant | 55 | Ramsey | 2524 | 351 | 2 |
| O'BRIEN | Bridget | 16 | Douglas | 2525 | 288 | 252 |
| O'BRIEN | Ellen | 35 | Onchan | 2525 | 49 | 159 |
| O'BRIEN | James | 21 | Douglas | 2525 | 288 | 252 |
| O'BRIEN | Mary | 56 | Douglas | 2525 | 288 | 252 |
| O'BRYAN | Michael | 19 | Douglas | 2525 | 263 | 25 |
| O'BRIEN | Sarah | 41 | Castletown | 2526 | 174 | 117 |
| O'BRIEN | Thomas | 14 | Douglas | 2525 | 288 | 252 |
| O'CONNOR | Charles | 28 | Douglas | 2525 | 324 | 145 |
| O'CONNOR | Dora | 1 | Douglas | 2525 | 323 | 142 |
| O'CONNOR | John | 12 | Castletown | 2526 | 112 | 3 |
| O'CONNOR | John | 1 | Douglas | 2525 | 324 | 145 |
| O'CONNOR | Margaret | 34 | Douglas | 2525 | 324 | 145 |
| O'CONNOR | Rose | 67 | Castletown | 2526 | 112 | 3 |
| O'DONNELLY | Mary | 47 | Onchan | 2525 | 27 | 17 |
| O'FLAGHERTY | Margaret | 18 | Onchan | 2525 | 38 | 90 |
| O'HARA | Ann | 39 | Douglas | 2525 | 289 | 258 |
| O'HARA | Catherine | 18 | Douglas | 2525 | 358 | 136 |
| O'HARA | Edward | 34 | Douglas | 2525 | 323 | 140 |
| O'HARA | Elizabeth | 6 | Douglas | 2525 | 358 | 136 |
| O'HARA | James | 9 | Douglas | 2525 | 358 | 136 |
| O'HARA | John | 20 | Douglas | 2525 | 358 | 136 |
| O'HARA | Joseph | 1 | Douglas | 2525 | 323 | 140 |
| O'HARA | Margaret | 48 | Douglas | 2525 | 358 | 136 |
| O'HARA | Richard | 5 | Douglas | 2525 | 358 | 136 |
| O'HARA | Robert | 64 | Douglas | 2525 | 358 | 136 |
| O'HARA | Robert | 14 | Douglas | 2525 | 358 | 136 |
| O'HARA | Sarah | 32 | Douglas | 2525 | 323 | 140 |
| O'HARE | Mary | 10 | Douglas | 2525 | 291 | 284 |
| OKELL | Elizabeth | 8 mos | Onchan | 2525 | 37 | 89 |
| OKELL | Jane | 26 | Onchan | 2525 | 37 | 89 |
| OKELL | Joseph | 26 | Onchan | 2525 | 37 | 89 |
| OKELL | Margaret | 59 | Onchan | 2525 | 81 | 129 |
| O'KELL | Margaret | 36 | Onchan | 2525 | 29 | 29 |
| O'KELL | Mary R. | 6 | Onchan | 2525 | 29 | 29 |
| O'KELL | William | 32 | Onchan | 2525 | 29 | 29 |
| O'MARA | Ann | 23 | Onchan | 2525 | 101 | 68 |
| O'MARRA | Margaret | 2 | Castletown | 2526 | 154 | 193 |
| O'NEIL | Catherine | 59 | Douglas | 2525 | 271 | 104 |
| O'NEIL | Ellen | 18 | Ramsey | 2524 | 318 | 77 |
| O'NEIL | Ellen | 26 | Onchan | 2525 | 41 | 115 |
| O'NIEL | Elizabeth | 25 | Douglas | 2525 | 358 | 135 |
| O'NEIL | Isabella | 28 | Peel | 2523 | 161 | 176 |
| O'NEIL | James | 65 | Douglas | 2525 | 324 | 149 |
| O'NIEL | Maurice | 35 | Douglas | 2525 | 358 | 135 |
| O'NIEL | Michael | 28 | Douglas | 2525 | 119 | 107 |
| O'NEIL | Patrick | 47 | Douglas | 2525 | 325 | 162 |
| O'NEILL | Sarah | 30 | Braddan | 2525 | 423 | 8 |
| O'ROURKE | Bridget | 40 | Douglas | 2525 | 253 | 317 |
| O'ROURKE | Bridget | 10 | Douglas | 2525 | 253 | 317 |
| O'ROURKE | Catherine | 13 | Douglas | 2525 | 253 | 317 |
| O'ROOKE | James | 7 | Douglas | 2525 | 292 | 285 |
| O'ROURKE | Margaret | 7 | Douglas | 2525 | 253 | 317 |
| O'ROOKE | Mary | 48 | Douglas | 2525 | 292 | 285 |
| O'ROURKE | Mary | 15 | Douglas | 2525 | 253 | 317 |
| O'ROURKE | Patrick | 40 | Douglas | 2525 | 253 | 317 |
| O'ROURKE | Patrick | 5 | Douglas | 2525 | 253 | 317 |
| O'TOOLE | Martin | 21 | Castletown | 2526 | 188 | 36 |
| OATES | Alice M. | 6 mos | Lonan | 2524 | 453 | 95 |
| OATES | Ann | 66 | Peel | 2523 | 109 | 55 |
| OATES | Ann | 57 | Braddan | 2525 | 424 | 14 |
| OATES | Ann | 54 | Onchan | 2525 | 11 | 51 |
| OATES | Ann | 50 | Michael | 2523 | 309 | 6 |
| OATES | Ann | 31 | Onchan | 2525 | 6 | 13 |
| OATES | Ann | 24 | Lonan | 2524 | 453 | 95 |
| OATES | Ann | 8 | Douglas | 2525 | 382 | 128 |
| OATES | Ann | 6 | Onchan | 2525 | 6 | 13 |
| OATES | Ann | 4 | Santon | 2525 | 500 | 37 |
| OATS | Ann | 2 | Onchan | 2525 | 8 | 36 |
| OATS | Ann | 8 mos | German | 2523 | 209 | 123 |
| OATES | Catherine | 84 | Malew | 2526 | 65 | 35 |
| OATES | Catherine | 55 | Douglas | 2525 | 218 | 10 |
| OATES | Catherine | 50 | Santon | 2525 | 500 | 37 |
| OATES | Catherine | 39 | Jurby | 2524 | 12 | 55 |
| OATES | Catherine | 34 | Braddan | 2525 | 424 | 14 |
| OATES | Catherine | 10 | Braddan | 2525 | 424 | 14 |
| OATES | Catherine | 10 | Santon | 2525 | 500 | 37 |
| OATES | Catherine | 1 | Douglas | 2525 | 361 | 164 |
| OATES | Christian | 23 | Bride | 2524 | 155 | 31 |
| OATES | Edward | 53 | Onchan | 2525 | 10 | 51 |
| OATES | Edward | 45 | Braddan | 2525 | 424 | 14 |
| OATES | Edward | 25 | Onchan | 2525 | 94 | 17 |
| OATES | Edward | 15 | Braddan | 2525 | 424 | 14 |
| OATES | Eleanor | 36 | Braddan | 2525 | 414 | 32 |
| OATES | Ellen | 27 | Onchan | 2525 | 40 | 106 |
| OATES | Eleanor | 23 | Peel | 2523 | 105 | 25 |
| OATES | Eleanor | 22 | Lonan | 2524 | 453 | 95 |
| OATES | Eleanor | 1 | Braddan | 2525 | 414 | 32 |
| OATES | Elinor | 1 | Lonan | 2524 | 454 | 102 |
| OATS | Elizabeth | 36 | German | 2523 | 209 | 123 |
| OATES | Elizabeth | 36 | Michael | 2523 | 309 | 6 |
| OATES | Elizabeth | 22 | Onchan | 2525 | 96 | 34 |
| OATES | Elizabeth | 19 | Onchan | 2525 | 11 | 51 |
| OATES | Elizabeth | 12 | Onchan | 2525 | 86 | 163 |
| OATES | Elizabeth | 8 | Braddan | 2525 | 414 | 32 |
| OATES | Elizabeth | 6 | Michael | 2523 | 334 | 3 |
| OATES | Elizabeth | 4 | Bride | 2524 | 153 | 13 |
| OATES | Esther | 16 | Braddan | 2525 | 414 | 32 |
| OATES | Esther | 6 | Onchan | 2525 | 95 | 26 |
| OATES | Frederick | 15 | Castletown | 2526 | 150 | 155 |
| OATES | Hannah | 24 | Peel | 2523 | 111 | 74 |
| OATES | Hannah | 1 | Braddan | 2525 | 424 | 14 |
| OATES | Henry | 12 | Santon | 2525 | 500 | 37 |
| OATES | Isabella | 33 | Michael | 2523 | 327 | 38 |
| OATES | Isabella | 7 | Braddan | 2525 | 424 | 14 |
| OATES | James | 58 | Michael | 2523 | 327 | 38 |
| OATES | James | 40 | Douglas | 2525 | 382 | 128 |
| OATES | James | 38 | Onchan | 2525 | 56 | 206 |
| OATES | James | 22 | Braddan | 2525 | 451 | 86 |
| OATES | James | 22 | German | 2523 | 219 | 29 |
| OATES | James | 22 | Peel | 2523 | 128 | 185 |
| OATES | James | 6 | Braddan | 2525 | 414 | 32 |
| OATES | Jane | 66 | Santon | 2525 | 490 | 52 |
| OATES | Jane | 57 | Michael | 2523 | 309 | 8 |
| OATES | Jane | 40 | Onchan | 2525 | 56 | 206 |
| OATES | Jane | 40 | Patrick | 2523 | 97 | 78 |
| OATES | Jane | 30 | Douglas | 2525 | 115 | 67 |
| OATES | Jane | 28 | Santon | 2525 | 500 | 37 |
| OATES | Jane | 26 | Onchan | 2525 | 77 | 103 |
| OATES | Jane | 17 | Michael | 2523 | 309 | 8 |
| OATES | John | 60 | Michael | 2523 | 309 | 8 |
| OATES | John | 56 | Douglas | 2525 | 286 | 235 |
| OATES | John | 40 | Braddan | 2525 | 414 | 32 |
| OATES | John | 40 | Onchan | 2525 | 6 | 13 |
| OATS | John | 34 | Onchan | 2525 | 8 | 36 |
| OATS | John | 24 | Rushen | 2526 | 308 | 75 |
| OATES | John | 21 | Braddan | 2525 | 433 | 78 |
| OATS | John | 10 | German | 2523 | 209 | 123 |
| OATES | John James | 8 | Michael | 2523 | 327 | 38 |
| OATES | John | 3 | Peel | 2523 | 111 | 74 |
| OATES | John | 1 | Onchan | 2525 | 6 | 13 |
| OATES | Margaret | 65 | Lezayre | 2524 | 226 | 6 |
| OATES | Margaret | 37 | Douglas | 2525 | 361 | 164 |
| OATS | Margaret | 28 | Onchan | 2525 | 8 | 36 |
| OATES | Margaret | 22 | Douglas | 2525 | 115 | 67 |
| OATES | Margaret | 22 | Lezayre | 2524 | 226 | 6 |
| OATES | Margaret | 20 | Ramsey | 2524 | 360 | 89 |
| OATES | Margaret | 19 | Michael | 2523 | 309 | 6 |
| OATES | Margaret | 12 | Braddan | 2525 | 446 | 47 |
| OATES | Margaret | 3 | Onchan | 2525 | 6 | 13 |
| OATES | Maria | 36 | Douglas | 2525 | 382 | 128 |
| OATES | Martha | 15 | Patrick | 2523 | 41 | 25 |
| OATES | Mary | 82 | Michael | 2523 | 309 | 6 |
| OATES | Mary | 64 | Douglas | 2525 | 115 | 67 |
| OATES | Mary | 50 | Patrick | 2523 | 41 | 25 |
| OATES | Mary A. | 30 | Lonan | 2524 | 454 | 102 |
| OATES | Mary Ann | 23 | Douglas | 2525 | 110 | 28 |
| OATES | Mary | 16 | Onchan | 2525 | 70 | 51 |
| OATES | Mary A. | 4 | Lonan | 2524 | 454 | 102 |
| OATES | Robert | 77 | Douglas | 2525 | 115 | 67 |
| OATES | Robert | 70 | Onchan | 2525 | 6 | 13 |
| OATES | Robert | 54 | Lezayre | 2524 | 226 | 6 |
| OATES | Robert | 34 | Michael | 2523 | 309 | 6 |
| OATS | Robert | 17 | Andreas | 2524 | 103 | 60 |
| OATES | Robert | 3 | Braddan | 2525 | 414 | 32 |
| OATS | Robert | 3 | German | 2523 | 209 | 123 |
| OATES | Susannah | 4 | Andreas | 2524 | 54 | 2 |
| OATES | Thomas | 70 | Santon | 2525 | 500 | 37 |
| OATS | Thomas | 47 | German | 2523 | 209 | 123 |
| OATES | Thomas | 46 | Michael | 2523 | 309 | 6 |
| OATES | Thomas | 34 | Santon | 2525 | 499 | 33 |
| OATES | Thomas | 28 | Lonan | 2524 | 454 | 102 |
| OATES | Thomas | 5 | Braddan | 2525 | 414 | 32 |
| OATES | Thomas | 5 | Onchan | 2525 | 6 | 13 |
| OATES | Thomas | 3 | Lonan | 2524 | 454 | 102 |
| OATES | William | 63 | Santon | 2525 | 490 | 52 |
| OATES | William | 50 | Patrick | 2523 | 41 | 25 |
| OATES | William | 25 | Lonan | 2524 | 453 | 95 |
| OATES | William | 24 | Santon | 2525 | 486 | 17 |
| OATES | William | 20 | Braddan | 2525 | 425 | 16 |
| OATES | William | 10 | Braddan | 2525 | 414 | 32 |
| OATES | William | 6 | Michael | 2523 | 310 | 18 |
| OATES | William | 5 | Braddan | 2525 | 424 | 14 |
| OATLAND | Sarah | 11 | Lonan | 2524 | 422 | 5 |
| OGDEN | Ayliner | 2 | Braddan | 2525 | 423 | 8 |
| OGDEN | Charles R. | 60 | Braddan | 2525 | 423 | 8 |
| OGDEN | John | 40 | Douglas | 2525 | 143 | 44 |
| OGDEN | Lynhurst | 4 | Braddan | 2525 | 423 | 8 |
| OGDEN | Richard Tynwald | 5 | Braddan | 2525 | 423 | 8 |
| OGDEN | Sarah Jane | 19 | Michael | 2523 | 296 | 25 |
| OGDEN | Susan | 42 | Braddan | 2525 | 423 | 8 |
| OGDEN | Susan Copley | 10 | Braddan | 2525 | 423 | 8 |
| OGILVIE | Agnes Jane | 5 mos | Douglas | 2525 | 326 | 169 |
| OGELBY | Delanby | 10 | Ramsey | 2524 | 358 | 67 |
| OGILVIE | George | 7 | Douglas | 2525 | 326 | 169 |
| OGILVIE | James | 9 | Douglas | 2525 | 326 | 169 |
| OLDENBOURG | George M. | 20 | Malew | 2526 | 43 | 63 |
| OLDRIGE | Elizabeth | 38 | Malew | 2526 | 49 | 100 |
| OLIVER | Alexander | 49 | Castletown | 2526 | 175 | 118 |
| OLIVER | Ann | 32 | Lonan | 2524 | 412 | 129 |
| OLIVER | Ann | 5 | Castletown | 2526 | 175 | 118 |
| OLIVER | Catherine | 1 | Lonan | 2524 | 412 | 129 |
| OLIVER | Emma | 45 | Braddan | 2525 | 400 | 60 |
| OLIVER | Hugh | 5 | Lonan | 2524 | 412 | 129 |
| OLIVER | James | 35 | Lonan | 2524 | 412 | 129 |
| OLIVER | John | 11 | Lonan | 2524 | 412 | 129 |
| OLIVER | Margaret | 4 | Lonan | 2524 | 412 | 129 |
| OLIVER | Mary | 70 | Ramsey | 2524 | 344 | 136 |
| OLIVER | Mary | 11 | Castletown | 2526 | 175 | 118 |
| OLIVER | Mary A. | 7 | Lonan | 2524 | 412 | 129 |
| OLIVER | Sarah | 47 | Castletown | 2526 | 175 | 118 |
| OLIVER | Sarah | 14 | Castletown | 2526 | 175 | 118 |
| OLIVER | Thomas | 23 | Lonan | 2524 | 413 | 135 |
| OLIVER | William J. | 9 | Castletown | 2526 | 175 | 118 |
| OLLIER | Elizabeth | 17 | Douglas | 2525 | 128 | 161 |
| OMAN | Ann | 51 | Onchan | 2525 | 73 | 76 |
| OMAN | Isabella J. | 13 | Onchan | 2525 | 73 | 76 |
| OMAN | Mary Ann | 15 | Onchan | 2525 | 73 | 76 |
| ORMEROD | Edgar | 12 | Douglas | 2525 | 345 | 15 |
| ORMEROD | Lucy Ann | 8 | Douglas | 2525 | 345 | 15 |
| ORMEROD | Mary | 49 | Douglas | 2525 | 345 | 15 |
| ORMEROD | Mary | 20 | Douglas | 2525 | 345 | 15 |
| ORMEROD | Sarah | 26 | Douglas | 2525 | 345 | 15 |
| OMEROD | Thomas | 15 | Douglas | 2525 | 333 | 229 |
| ORE | Ellen | 72 | Malew | 2526 | 12 | 63 |
| ORR | Elizabeth | 46 | Douglas | 2525 | 334 | 237 |
| ORR | Elizabeth | 34 | Douglas | 2525 | 119 | 104 |
| ORE | Elizabeth | 5 | Castletown | 2526 | 125 | 112 |
| ORR | James | 26 | Lonan | 2524 | 456 | 115 |
| ORE | James | 24 | Marown | 2523 | 283 | 49 |
| ORR | James | 22 | Castletown | 2526 | 188 | 37 |
| ORE | John | 72 | Malew | 2526 | 12 | 63 |
| ORE | John A. | 3 | Braddan | 2525 | 398 | 44 |
| ORE | Margaret | 25 | Marown | 2523 | 283 | 49 |
| ORR | Mary | 5 | Lonan | 2524 | 446 | 45 |
| ORE | Mary Ann | 1 mon | Marown | 2523 | 283 | 49 |
| ORE | Rebecca | 3 | Castletown | 2526 | 125 | 112 |
| ORE | Richard | 32 | Castletown | 2526 | 125 | 112 |
| ORE | Richard | 1 | Castletown | 2526 | 125 | 112 |
| ORE | Sarah | 38 | Castletown | 2526 | 125 | 112 |
| ORE | Sarah | 33 | Braddan | 2525 | 398 | 44 |
| ORE | Sarah | 7 | Castletown | 2526 | 125 | 112 |
| ORE | Sarah Jane | 5 | Braddan | 2525 | 398 | 44 |
| ORE | Thomas | 1 | Braddan | 2525 | 398 | 44 |
| ORE | William | 41 | Braddan | 2525 | 398 | 44 |
| ORFOTH | Samuel | 30 | Douglas | 2525 | 139 | 12 |
| ORMSBY | Arthur | 58 | Malew | 2526 | 51 | 114 |
| ORMSBY | Rose J. | 57 | Malew | 2526 | 51 | 114 |
| ORMSTEAD | Ann | 28 | German | 2523 | 221 | 44 |
| ORMSTEAD | Edward | 28 | German | 2523 | 221 | 44 |
| ORMSTEAD | Edward | 10 mos | German | 2523 | 221 | 44 |
| ORMSTEAD | Mary Jane | 2 | German | 2523 | 221 | 44 |
| OSBORN | Jane | 28 | Lonan | 2524 | 397 | 22 |
| OSBORN | William | 30 | Lonan | 2524 | 397 | 22 |
| OSWALD | Elizabeth | 45 | Douglas | 2525 | 126 | 151 |
| OSWALD | Francis C. | 21 | Douglas | 2525 | 126 | 151 |
| OSWALD | Henry R. | 60 | Douglas | 2525 | 126 | 151 |
| OSWALD | Johanna J. | 13 | Douglas | 2525 | 126 | 151 |
| OSWALD | Sarah F. | 50 | Douglas | 2525 | 126 | 151 |
| OSWALD | William W. | 10 | Douglas | 2525 | 126 | 151 |
| OUSEY | James | 22 | Douglas | 2525 | 120 | 107 |
| OWAN | Catherine | 83 | Malew | 2526 | 55 | 132 |
| OWEN | George | 84 | Onchan | 2525 | 44 | 131 |
| OWEN | Jane C. | 21 | Onchan | 2525 | 32 | 49 |
| OWAN | John | 87 | Malew | 2526 | 55 | 132 |
| OWENS | Ellen | 20 | Douglas | 2525 | 219 | 11 |
| OWENS | Eunice | 43 | Douglas | 2525 | 376 | 70 |
| OWENS | Henry | 45 | Santon | 2525 | 490 | 54 |
| OWENS | John | 45 | Douglas | 2525 | 376 | 70 |
| OWENS | Judith | 21 | Castletown | 2526 | 145 | 114 |
| OWENS | Sarah | 52 | Santon | 2525 | 490 | 54 |
| OWGARD | Joseph | 27 | Castletown | 2526 | 187 | 1 |