1901 Census - surnames beginning with O
| Last Name | First Name | Age | Parish | Piece | Folio | Page |
| O'BRIAN | Sarah | 22 | Ramsey | 5307 | 112 | 30 |
| O'BRIEN | Teresa | 18 | Onchan | 5302 | 127 | 72 |
| O'CONNOR | Catherine | 75 | Douglas | 5305 | 87 | 69 |
| O'CONNOR | Catherine | 21 | Ramsey | 5307 | 115 | 85 |
| O'CONNOR | Elizabeth | 23 | Douglas | 5305 | 128 | 101 |
| O'CONNOR | Emily | 48 | Douglas | 5305 | 128 | 101 |
| O'CONNOR | Emily | 24 | Douglas | 5305 | 128 | 101 |
| O'CONNOR | Margaret | 62 | Douglas | 5305 | 120 | 18 |
| O'CONNOR | Mary | 16 | Douglas | 5305 | 128 | 101 |
| O'CONNOR | Philip | 48 | Douglas | 5305 | 128 | 101 |
| O'CONNOR | William J | 21 | Douglas | 5305 | 128 | 101 |
| O'HAGAN | Margaret | 28 | Douglas | 5303 | 115 | 57 |
| O'HAGAN | Margaret | 2 | Douglas | 5303 | 115 | 57 |
| O'HAGHAN | Mary | 54 | Douglas | 5303 | 72 | 127 |
| O'HAGHAN | Mary | 16 | Douglas | 5303 | 72 | 127 |
| O'HAGAN | Mary | 3 | Douglas | 5303 | 115 | 57 |
| O'HAGAN | Patrick | 31 | Douglas | 5303 | 115 | 57 |
| O'HALLORAN | Jane | 71 | Maughold | 5302 | 19 | 65 |
| O'HALLOREN | Mary | 60 | Braddan | 5301 | 52 | 14 |
| O'HALLORAN | Mary | 11 mos | Castletown | 5308 | 130 | 89 |
| O'HALLORAN | Michael | 74 | Maughold | 5302 | 19 | 65 |
| O'HARA | Alfred | 18 | Douglas | 5305 | 92 | 151 |
| O'HARA | Annie | 54 | Douglas | 5303 | 83 | 9 |
| O'HARA | Annie | 28 | Rus | 5301 | 91 | 100 |
| O'HARA | Ellen | 55 | Douglas | 5304 | 91 | 170 |
| O'HARA | Eleanor | 50 | Douglas | 5305 | 92 | 151 |
| O'HARA | Eleanor | 20 | Douglas | 5305 | 92 | 151 |
| O'HARA | Elizabeth | 14 | Douglas | 5305 | 92 | 151 |
| O'HARA | Hannah M | 65 | Douglas | 5303 | 32 | 105 |
| O'HARA | John | 60 | Douglas | 5303 | 83 | 9 |
| O'HARA | Richard | 50 | Douglas | 5305 | 92 | 151 |
| O'HARA | Robert | 29 | Douglas | 5305 | 92 | 151 |
| O'HARA | Thomas | 23 | Douglas | 5305 | 92 | 151 |
| O'HARE | Isabella | 35 | Douglas | 5305 | 65 | 142 |
| O'HARE | John | 1 | Douglas | 5305 | 65 | 142 |
| O'HARE | Luke | 29 | Douglas | 5305 | 65 | 142 |
| O'HARE | Margaret | 3 | Douglas | 5305 | 65 | 142 |
| O'HARE | Thomas | 40 | Peel | 5308 | 153 | 63 |
| O'KEEFE | Margaret | 32 | Douglas | 5305 | 104 | 1 |
| OKELL | Ada | 43 | Douglas | 5304 | 95 | 222 |
| OKELL | Ada M | 19 | Douglas | 5304 | 95 | 222 |
| OKELL | Alfred W | 21 | Douglas | 5304 | 95 | 222 |
| OKELL | Charles P | 36 | Douglas | 5304 | 111 | 138 |
| OKELL | Charles C | 12 | Douglas | 5304 | 111 | 138 |
| OKELL | Marianne | 37 | Douglas | 5304 | 111 | 138 |
| OKELL | Robert | 57 | Onchan | 5302 | 115 | 56 |
| OKELL | William Henry | 48 | Douglas | 5304 | 95 | 222 |
| OKELL | William | 9 | Douglas | 5304 | 111 | 138 |
| O'NEILL | Annie | 34 | Rus | 5301 | 92 | 114 |
| O'NEILL | Hugh Joseph | 30 | Douglas | 5304 | 118 | 28 |
| O'NEIL | James | 62 | Douglas | 5303 | 40 | 221 |
| O'NEILL | James | 14 | Douglas | 5304 | 69 | 184 |
| O'NEILL | John | 57 | Douglas | 5304 | 69 | 184 |
| O'NEILL | Mary | 57 | Douglas | 5304 | 69 | 184 |
| O'NEIL | Mary | 34 | Douglas | 5303 | 40 | 221 |
| O'NEILL | Mary | 22 | Onchan | 5302 | 92 | 226 |
| O'NEILL | Mary | 19 | Douglas | 5304 | 69 | 184 |
| O'NEILL | Michael | 22 | Braddan | 5301 | 10 | 65 |
| O'NEILL | Percival J | 8 | Rus | 5301 | 92 | 114 |
| O'NEILL | Thomas | 17 | Douglas | 5304 | 69 | 184 |
| O'SHAUGNESEY | James | 36 | Douglas | 5305 | 97 | 234 |
| O'SHAUGNESEY | James T | 1 | Douglas | 5305 | 97 | 234 |
| O'SHAUGNESEY | Jane | 35 | Douglas | 5305 | 97 | 234 |
| O'SHAUGNESEY | John D | 5 | Douglas | 5305 | 97 | 234 |
| O'SHAUGNESEY | Mary A | 3 | Douglas | 5305 | 97 | 234 |
| O'SHEA | Mary J | 36 | Douglas | 5305 | 99 | 264 |
| O'SHEA | May F | 17 | Douglas | 5305 | 99 | 264 |
| O'SHEE | Thomas | 3 | Ballaugh | 5300 | 50 | 7 |
| OAKDEN | Ann | 70 | Douglas | 5303 | 84 | 22 |
| OAKDEN | Robert E | 36 | Douglas | 5303 | 84 | 22 |
| OATES | Aggie | 5 | Douglas | 5304 | 85 | 87 |
| OATES | Alice | 29 | Douglas | 5304 | 37 | 180 |
| OATES | Alice | 21 | Braddan | 5301 | 7 | 33 |
| OATES | Alman K | 3 | Malew | 5308 | 35 | 36 |
| OATES | Amy | 23 | Onchan | 5302 | 131 | 120 |
| OATES | Amy Catherine | 4 | Castletown | 5308 | 101 | 43 |
| OATES | Amy E | 3 | Lezayre | 5300 | 101 | 2 |
| OATES | Ann | 53 | Braddan | 5301 | 7 | 33 |
| OATES | Blanche E | 29 | Douglas | 5304 | 33 | 111 |
| OATES | Catherine J | 77 | Lezayre | 5300 | 79 | 30 |
| OATES | Catherine | 66 | Malew | 5308 | 87 | 45 |
| OATES | Catherine | 65 | Douglas | 5304 | 33 | 111 |
| OATES | Catherine | 24 | Douglas | 5303 | 54 | 84 |
| OATES | Christian | 60 | Castletown | 5308 | 141 | 108 |
| OATES | Edith E | 26 | Douglas | 5304 | 29 | 50 |
| OATES | Edmund | 18 | Douglas | 5304 | 92 | 176 |
| OATES | Eddie | 10 | Malew | 5308 | 35 | 36 |
| OATES | Edwin | 16 | Lonan | 5307 | 27 | 72 |
| OATES | Edwin A | 11 mos | Lezayre | 5300 | 101 | 2 |
| OATES | Eleanor C | 21 | Douglas | 5303 | 27 | 35 |
| OATES | Eliza | 53 | Onchan | 5302 | 114 | 54 |
| OATS | Elizabeth | 52 | Douglas | 5305 | 113 | 132 |
| OATES | Emily | 20 | Onchan | 5302 | 114 | 54 |
| OATES | Esther C | 25 | Douglas | 5304 | 92 | 176 |
| OATES | Ethel | 2 | Douglas | 5303 | 54 | 84 |
| OATES | Eunice | 38 | Lonan | 5307 | 27 | 70 |
| OATES | Eunice | 11 | Lonan | 5307 | 27 | 70 |
| OATES | Florence | 20 | Douglas | 5304 | 85 | 87 |
| OATES | Frances | 25 | Onchan | 5302 | 114 | 54 |
| OATES | Frank | 16 | Malew | 5308 | 35 | 36 |
| OATES | Fred | 24 | Douglas | 5303 | 54 | 84 |
| OATS | George | 18 | Onchan | 5302 | 115 | 61 |
| OATES | Henry | 12 | Malew | 5308 | 35 | 36 |
| OATES | Henry | 5 | Braddan | 5301 | 7 | 33 |
| OATES | Hilda | 12 | Lonan | 5307 | 27 | 70 |
| OATES | Isalen | 14 | Douglas | 5304 | 92 | 176 |
| OATES | James | 72 | Douglas | 5305 | 18 | 174 |
| OATES | James | 56 | Onchan | 5302 | 131 | 120 |
| OATES | James | 45 | Douglas | 5304 | 92 | 176 |
| OATES | James R | 27 | Douglas | 5304 | 29 | 50 |
| OATES | James | 12 | Braddan | 5301 | 7 | 33 |
| OATES | James N | 4 | Douglas | 5303 | 69 | 82 |
| OATES | Jane | 45 | Douglas | 5304 | 92 | 176 |
| OATES | Jane | 32 | Douglas | 5305 | 18 | 174 |
| OATES | Jedueth | 31 | Lezayre | 5300 | 101 | 2 |
| OATES | Jennie | 28 | Onchan | 5302 | 114 | 54 |
| OATES | Jessie | 7 | Patrick | 5306 | 128 | 20 |
| OATES | John | 68 | Douglas | 5304 | 33 | 111 |
| OATES | John J | 58 | Onchan | 5302 | 114 | 54 |
| OATES | John | 30 | Douglas | 5303 | 69 | 82 |
| OATES | John | 24 | Douglas | 5304 | 85 | 82 |
| OATES | John James | 24 | Douglas | 5304 | 92 | 176 |
| OATES | John James | 24 | Onchan | 5302 | 114 | 54 |
| OATES | John | 24 | Peel | 5308 | 154 | 71 |
| OATES | John James | 22 | Lonan | 5307 | 54 | 8 |
| OATES | John | 16 | Douglas | 5304 | 85 | 87 |
| OATES | John William | 6 | Castletown | 5308 | 101 | 43 |
| OATES | John | 1 | Douglas | 5303 | 54 | 84 |
| OATES | John W | 7 mos | Douglas | 5303 | 69 | 82 |
| OATES | Leonard | 12 | Douglas | 5304 | 85 | 87 |
| OATES | Lilian M | 4 | Malew | 5308 | 35 | 36 |
| OATES | Louisa | 66 | Ramsey | 5307 | 103 | 185 |
| OATES | Louisa | 31 | Castletown | 5308 | 101 | 43 |
| OATES | Margaret | 78 | Maughold | 5302 | 24 | 21 |
| OATES | Margaret E | 44 | Malew | 5308 | 35 | 36 |
| OATES | Margaret | 27 | Douglas | 5304 | 92 | 176 |
| OATES | Margaret A | 18 | Onchan | 5302 | 156 | 123 |
| OATES | Maggie | 9 | Lonan | 5307 | 27 | 70 |
| OATES | Mary | 80 | Douglas | 5305 | 137 | 60 |
| OATES | Mary A | 65 | Douglas | 5304 | 29 | 50 |
| OATES | Mary | 60 | Douglas | 5304 | 80 | 16 |
| OATES | Mary A | 51 | Douglas | 5305 | 124 | 50 |
| OATES | Mary | 30 | Douglas | 5303 | 69 | 82 |
| OATES | Mary | 24 | Douglas | 5304 | 85 | 82 |
| OATES | Matilda | 55 | Patrick | 5306 | 128 | 20 |
| OATES | Maud M | 23 | Douglas | 5304 | 29 | 50 |
| OATES | Mona I | 5 mos | Malew | 5308 | 35 | 36 |
| OATES | Robert | 53 | Braddan | 5301 | 7 | 33 |
| OATES | Robert | 52 | Douglas | 5305 | 61 | 129 |
| OATES | Robert Clucas | 32 | Castletown | 5308 | 101 | 43 |
| OATES | Robert | 20 | Douglas | 5304 | 92 | 176 |
| OATES | Robert | 14 | Douglas | 5304 | 85 | 87 |
| OATES | Robert A | 12 | Douglas | 5305 | 38 | 133 |
| OATES | Robert James | 1 | Castletown | 5308 | 101 | 43 |
| OATES | Susan A | 37 | Douglas | 5304 | 127 | 137 |
| OATES | Thomas | 54 | Douglas | 5304 | 85 | 87 |
| OATES | Thomas | 23 | Douglas | 5304 | 85 | 87 |
| OATES | Thomas | 20 | Patrick | 5306 | 147 | 4 |
| OATES | Vida C | 1 | Douglas | 5304 | 92 | 176 |
| OATES | Walter | 33 | Douglas | 5305 | 18 | 174 |
| OATES | William | 57 | Douglas | 5304 | 13 | 90 |
| OATES | William H | 46 | Malew | 5308 | 35 | 36 |
| OATES | William | 36 | Lonan | 5307 | 27 | 70 |
| OATES | William | 29 | Peel | 5308 | 150 | 38 |
| OATES | William H | 25 | Douglas | 5303 | 27 | 35 |
| OATS | William A | 20 | Lonan | 5307 | 47 | 1 |
| OATES | William R | 13 | Malew | 5308 | 35 | 36 |
| OATES | William | 8 | Lonan | 5307 | 27 | 70 |
| OATES | William K | 4 | Lezayre | 5300 | 101 | 2 |
| OGDEN | Charlotte | 28 | Douglas | 5303 | 134 | 100 |
| OGDEN | Lena | 10 | Rus | 5301 | 69 | 45 |
| OGG | Barbara | 27 | Onchan | 5302 | 103 | 50 |
| OHEA | Louisa | 24 | Douglas | 5305 | 143 | 126 |
| OLDALE | Anne | 45 | Braddan | 5301 | 61 | 204 |
| OLDALE | John | 55 | Douglas | 5303 | 7 | 35 |
| OLDALE | Joseph | 24 | Douglas | 5303 | 7 | 35 |
| OLDAM | Alice | 22 | Malew | 5308 | 77 | 52 |
| OLDHAM | Rosey | 17 | Braddan | 5301 | 7 | 29 |
| OLIPHANT | Catherine | 36 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | Catherine A | 10 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | Eleanor J | 15 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | Ethel Maud | 5 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | Florence M | 8 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | Joshua | 42 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | Lilian M | 1 | Maughold | 5302 | 8 | 41 |
| OLIPHANT | William H | 10 | Maughold | 5302 | 8 | 41 |
| OLIVER | Benjamin | 10 | Lonan | 5307 | 24 | 31 |
| OLIVER | Elijah | 15 | Lonan | 5307 | 24 | 31 |
| OLIVER | Elizabeth | 49 | Lonan | 5307 | 24 | 31 |
| OLIVER | Henrietta B | 26 | Michael | 5300 | 7 | 36 |
| OLIVER | Joseph | 22 | Peel | 5308 | 154 | 68 |
| OLIVER | Joshua E | 19 | Lonan | 5307 | 24 | 31 |
| OLLERENSHAW | Beatrice | 24 | Rus | 5301 | 117 | 27 |
| OLLERENSHAW | Elizabeth | 62 | Braddan | 5301 | 25 | 83 |
| OLLERENSHAW | James | 60 | Braddan | 5301 | 25 | 83 |
| OLLERENSHAW | Olive | 21 | Rus | 5301 | 117 | 27 |
| ORMEROD | Alfred S | 50 | Rus | 5301 | 69 | 45 |
| ORMEROD | Lucy E | 51 | Rus | 5301 | 69 | 45 |
| OPENSHAW | Margaret | 90 | Rus | 5301 | 110 | 172 |
| ORAM | Alfred | 26 | Ramsey | 5307 | 182 | 213 |
| ORAM | Elizabeth | 3 | Ramsey | 5307 | 182 | 213 |
| ORAM | Frances | 25 | Ramsey | 5307 | 182 | 213 |
| ORR | Annie | 24 | Douglas | 5305 | 143 | 124 |
| ORR | Elizabeth | 52 | Braddan | 5301 | 21 | 32 |
| ORR | Esther | 74 | German | 5306 | 87 | 32 |
| ORR | James | 70 | Braddan | 5301 | 21 | 32 |
| ORR | John | 76 | German | 5306 | 87 | 32 |
| ORR | Thomas | 46 | Patrick | 5306 | 147 | 4 |
| ORGAN | George | 22 | Douglas | 5304 | 127 | 145 |
| ORME | Mary | 18 | Douglas | 5305 | 142 | 113 |
| ORMERATH | Sarah | 79 | Douglas | 5304 | 112 | 144 |
| ORMISTON | Elizabeth | 48 | Onchan | 5302 | 93 | 241 |
| ORRETT | Annie | 29 | Onchan | 5302 | 81 | 56 |
| ORRETT | Clara | 38 | Onchan | 5302 | 84 | 92 |
| ORRETT | Eliza | 60 | Onchan | 5302 | 81 | 56 |
| ORRETT | Elizabeth | 27 | Douglas | 5303 | 5 | 1 |
| ORRETT | Ethel | 11 | Onchan | 5302 | 84 | 92 |
| ORRGAN | Sarah | 45 | Peel | 5306 | 19 | 224 |
| OSBORNE | Abraham Gordon | 26 | Onchan | 5302 | 122 | 17 |
| OSBORNE | Annie | 26 | Douglas | 5303 | 114 | 45 |
| OSBORNE | Ann | 2 | Douglas | 5303 | 114 | 45 |
| OSBORNE | Charles C | 41 | Michael | 5300 | 8 | 54 |
| OSBORNE | Harriet | 36 | Onchan | 5302 | 155 | 115 |
| OSBORNE | Jessie | 23 | Onchan | 5302 | 122 | 17 |
| OSBOURNE | John F | 43 | Douglas | 5303 | 6 | 23 |
| OSBORNE | Loria | 19 | Onchan | 5302 | 155 | 115 |
| OSBOURNE | Margaret E | 45 | Douglas | 5303 | 6 | 23 |
| OSBORNE | Thomas | 54 | Onchan | 5302 | 155 | 115 |
| OSBORNE | Thomas | 26 | Douglas | 5303 | 114 | 45 |
| OSBORNE | Thomas | 2 wks | Douglas | 5303 | 114 | 45 |
| OSBORNE | William | 21 | Onchan | 5302 | 155 | 115 |
| OSBORNE | William | 4 | Douglas | 5303 | 114 | 45 |
| OTTERWELL | Olive M | 10 | Lonan | 5307 | 48 | 16 |
| OTTERWELL | Thomas | 47 | Lonan | 5307 | 48 | 16 |
| OWEN | Anne | 66 | Lonan | 5307 | 38 | 10 |
| OWEN | Elizabeth | 36 | Lonan | 5307 | 38 | 10 |
| OWEN | Emily | 32 | Douglas | 5304 | 45 | 27 |
| OWEN | John | 25 | Patrick | 5306 | 138 | 16 |
| OWEN | Richard | 35 | Douglas | 5304 | 45 | 27 |
| OWEN | Rose A | 41 | Rus | 5301 | 69 | 45 |
| OWEN | Thomas Richard | 26 | Patrick | 5306 | 158 | 123 |
| OWENS | Emily | 48 | Douglas | 5305 | 126 | 76 |
| OWENS | Eva | 15 | Douglas | 5305 | 126 | 76 |
| OWENS | John | 45 | Malew | 5308 | 50 | 64 |
| OWENS | Mabel | 8 | Douglas | 5305 | 126 | 76 |
| OWENS | William J | 21 | Patrick | 5306 | 137 | 6 |
| OXENFORD | Ada | 30 | Douglas | 5304 | 133 | 217 |
| OXENFORD | Ada D | 13 | Douglas | 5304 | 133 | 217 |
| OXLEY | Eliza | 29 | Douglas | 5303 | 126 | 9 |