| 5989 | Oakley, Craig | Unknown | Unknown |
| 5990 | Oakley, Darren G | Unknown | Unknown |
| 5988 | Oakley, Peter | Unknown | Unknown |
| 2833 | Oates, Albert | Barnsley | 1867 |
| 2104 | Oates, Elizabeth | Emley | 1730 |
| 2836 | Oates, Ernest O | Barnsley | 1875 |
| 2832 | Oates, George Henry | Barnsley | 1865 |
| 7211 | Oates, George Arthur | Barnsley | 1881 |
| 2837 | Oates, Herbert | Barnsley | 1878 |
| 7112 | Oates, Lilian | Barnsley | 1870 |
| 7113 | Oates, Rose | Barnsley | 1870 |
| 7212 | Oates, Rowland | Barnsley | 1883 |
| 2834 | Oates, Walter | Barnsley | 1871 |
| 2831 | Oates, William | Royston | 1836 |
| 2835 | Oates, William Thomas | Barnsley | 1873 |
| 5365 | O'Connor, Mary H | Wisconsin, America | 1883 |
| 472 | O'Kane, Chloe | Ireland | Still Living |
| 471 | O'Kane, Peter | Ireland | Unknown |
| 5673 | Oldfield, Agnes | Lindley, Yorkshire | 1892 |
| 5677 | Oldfield, Arthur | Huddersfield District | Still Living |
| 5675 | Oldfield, Edgar | Lindley, Yorkshire | 1898 |
| 5674 | Oldfield, Joseph | Lindley, Yorkshire | 1896 |
| 5676 | Oldfield, Lucy | Ainley Top, Elland, Leeds | 1901 |
| 5672 | Oldfield, Samuel | Lindley, Yorkshire | 1866 |
| 4024 | Oldridge, Aaron William | Unknown | Still Living |
| 4023 | Oldridge, Christina | Unknown | Still Living |
| 3914 | Oldridge, Gregory | Unknown | Still Living |
| 3912 | Oldridge, Karen | Unknown | Still Living |
| 3913 | Oldridge, Kay | Unknown | Still Living |
| 3911 | Oldridge, Lorraine | Unknown | Still Living |
| 3910 | Oldridge, Terrence | Unknown | Unknown |
| 1287 | Oliver, Evelyn Patricia | Canada | Still Living |
| 1289 | Oliver, James David | Canada | Still Living |
| 1286 | Oliver, Jane Dianne | Canada | Still Living |
| 1285 | Oliver, John Douglas | Canada | Unknown |
| 1288 | Oliver, John William | Canada | Still Living |
| 965 | Oliver, Stephen | Unknown | Unknown |
| 3487 | O'Neill, Doreen Elaine | Perth, Australia | 1933 |
| 3030 | O'Neill, Karen B | Pontefract | Still Living |
| 496 | O'Neill, Liam | Ireland | Unknown |
| 3486 | O'Neill, Thomas | Unknown | Unknown |
| 2747 | Orrin, Kezia | Colchester | 1856 |
| 3498 | Osborne, Donna | Unknown | Unknown |
| 4224 | O'Shea, Daniel John Hardman | Ormskirk, Lancashire | Still Living |
| 4222 | O'Shea, David John | Southport | Still Living |
| 4220 | O'Shea, Deanna Lynette | Southport | Still Living |
| 4225 | O'Shea, Grace Louise Hardman | Ormskirk, Lancashire | Still Living |
| 4221 | O'Shea, Kerry Louise | Southport | Still Living |
| 4218 | O'Shea, Michael John | Southport | Still Living |
| 4219 | O'Shea, Wayne Michael | Plymouth, Devon | Still Living |
| 4196 | Ostcliffe, Ann | Elsecar | 1881 |
| 4576 | Owen, Beatrice | Sheffield | 1928 |
| 3082 | Owen, Rita Charlotte | Australia | 1904 |
| 3166 | Owens, Agnes | Australia | Unknown |
| 3218 | Owens, Ann | Barnsley | 1828 |
| 651 | Owens, Thomas | Barnsley | Unknown |
| 7225 | Oxley, Ellen Elizabeth | Sheffield | 1866 |
| 5558 | Oxley, Ernest | Unknown | Unknown |
| 5678 | Oxley, George | Unknown | Unknown |
| 5679 | Oxley, Sally | Penistone District | Still Living |
| 2211 | Oxtaby, Ann | Barnsley | 1823 |
| 7210 | Oxtaby, Blanche | Barnsley | 1887 |
| 2213 | Oxtaby, Elizabeth | Barnsley | 1829 |
| 2208 | Oxtaby, George | Barnsley | 1815 |
| 2841 | Oxtaby, George Edward | Barnsley | 1879 |
| 2648 | Oxtaby, Harry | Barnsley | 1853 |
| 2840 | Oxtaby, Herbert Harry | Barnsley | 1877 |
| 3017 | Oxtaby, James | Barnsley | 1836 |
| 7208 | Oxtaby, Jane Ann | Barnsley | 1882 |
| 2210 | Oxtaby, John | Barnsley | 1822 |
| 2647 | Oxtaby, Mary Ann | Barnsley | 1843 |
| 7209 | Oxtaby, Mary Alice | Barnsley | 1884 |
| 2209 | Oxtaby, Sarah | Barnsley | 1819 |
| 2206 | Oxtaby, Thomas | Buxton, Derbyshire | 1793 |
| 2212 | Oxtaby, William | Barnsley | 1826 |
| 2611 | Oxtaby, William | Barnsley | 1844 |
Correct as at 03 March, 2010