| Branch | Birth | Death | Name | Spouse |
| 35 | Okey (15) | |||
| 3 | 1908 | Okla Maxine (509) | ||
| Note 3 | 1942 | Ola Faye (75) | G. W. Grimmett, Jr. | |
| 37 | 1899 | Oliva Marie (23) | Paul Nicholas White | |
| 37 | 1846 | Olive (12) | ||
| 37 | 1846 | Olive (3) | Andrew Craig | |
| 45 | infant | infant | Olive (42) | |
| 41 | 1921 | Olive Jean (33) | ||
| 3 | Olive Marguerite (483) | T. Allan Ross | ||
| 4 | 1871 | Olive May (252) | Benjamin Van Tassel | |
| 15 | Oliver C. (49) | |||
| 1 | 1902 | Oliver Keith (341) | ||
| 1 | 1879 | Oliver Lyman (321) | ||
| 1 | 1877 | Oliver Perry (82) | Catherine M. Hadlock | |
| 28 | 1892 | Ollie (97) | ||
| 45 | Ollie J. (33) | Samuel Teagarden Chester | ||
| 29 | 1906 | Ollie Oletia (102) | ||
| 7 | 1934 | Ollie Ray (270) | ||
| 29 | Omar (72) | |||
| 9 | Omar (88) | |||
| 28 | 1890 | Omie (96) | Dilliard Craven | |
| 17 | 1926 | Onie Mary (127) | Arthur Brooks Lunsford | |
| 1 | Opal (357) | Charles Brushaber | ||
| 1 | 1917 | Opal (385) | ||
| Note 3 | Opal (49) | |||
| Note 3 | 1932 | 1932 | Opal (52) | |
| 17 | 1920 | Opal Virginia (278) | Jack Madill Spicer | |
| 24 | 1879 | Ora Edith (25) | Charles Rice | |
| 3 | 1868 | Ora Iona (353) | ||
| 22 | 1891 | 1980 | Ora S. (38) | Teresa Dahms |
| 51 | 1958 | Orbie (48) | ||
| 1 | 1895 | Orta Leila (338) | James Sullivan | |
| 3 | Orvilla (276) | |||
| 3 | Osborn (366) | |||
| 1 | 1868 | 1954 | Oscar (70) | Amanda Mae Jeter |
| 1 | 1868 | 1954 | Oscar (70) | Mamie Earwood |
| 3 | 1893 | Oscar Ellsworth (447) | ||
| 1 | 1904 | Oscar James (379) | Vesta Mae LaRue | |
| 6 | Osella (104) | |||
| 13 | 1880 | 1931 | Osgood Stanley (141) | Edith Alberta Holley |
| 45 MB/9 | 1836 | 1866 | Ostrander D. (4) | Mary M. Allen |
| 3 | 1870 | 1900 | Otis D. (343) | |
| 1 | 1872 | Otto Mansfield (71) | Grace G. McCarty | |
| 22 | Otto R. (35) |