| Author | Profession | Birth date | Death date |
|---|---|---|---|
| O'Shea Jackson, Jr. | American Actor | February 24, 1991 | |
| O. Carl Simonton | June 29, 1942 | June 18, 2009 | |
| O. Henry | American Writer | September 11, 1862 | June 5, 1910 |
| O. J. Brigance | Football player | September 29, 1969 | |
| O. J. Simpson | American Athlete | July 9, 1947 | |
| O. Leslie Stone | May 28, 1903 | April 26, 1986 | |
| O. P. Kretzmann | Author | May 7, 1901 | September 14, 1975 |
| O. R. Melling | Irish Author | ||
| O. S. Hawkins | Author | August 16, 1947 | |
| O. Winston Link | American Photographer | December 16, 1914 | January 30, 2001 |
| O.C. | Rapper | 1973 | |
| O.R. Melling | Author | ||
| Obafemi Awolowo | Nigerian statesman | March 6, 1909 | May 9, 1987 |
| Obert C. Tanner | September 20, 1904 | October 14, 1993 | |
| Obert Skye | Author | ||
| Obiageli Ezekwesili | Nigerian Public Servant | April 28, 1963 | |
| Obie Trice | American Musician | November 14, 1977 | |
| Octave Chanute | Engineer | February 18, 1832 | November 23, 1910 |
| Octave Feuillet | Novelist | August 11, 1821 | December 29, 1890 |
| Octave Mirbeau | French Writer | February 16, 1848 | February 16, 1917 |
| Octave Pirmez | 1832 | ||
| Octavia Butler | American Writer | June 22, 1947 | February 24, 2006 |
| Octavia E. Butler | American Writer | June 22, 1947 | February 24, 2006 |
| Octavia Spencer | American Actress | May 25, 1970 | |
| Octavia St. Laurent | Film actor | March 16, 1964 | May 17, 2009 |
| Octavian Paler | Romanian Writer | July 2, 1926 | May 7, 2007 |
| Octavio Paz | Mexican Poet | March 31, 1914 | April 19, 1998 |
| Octavius Black | May 2, 1968 | ||
| Octavius Winslow | August 1, 1808 | March 5, 1878 | |
| Oda Nobunaga | Daimyo | June 23, 1534 | June 21, 1582 |
| Odd Nerdrum | Painter | April 8, 1944 | |
| Oded Fehr | Israeli Actor | November 23, 1970 | |
| Odell Shepard | Professor | July 22, 1884 | July 19, 1967 |
| Odetta | Singer | December 31, 1930 | December 2, 2008 |
| Odette Annable | American Actress | May 10, 1985 | |
| Odeya Rush | Israeli Actress | May 12, 1997 | |
| Odile Decq | July 18, 1955 | ||
| Odilo Globocnik | Political leader | April 21, 1904 | May 31, 1945 |
| Odilon Redon | French Artist | April 20, 1840 | July 6, 1916 |
| Odo of Cluny | Abbot | 878 | November 18, 942 |
| Odysseas Elytis | November 2, 1911 | March 18, 1996 | |
| Oenomaus | Rebel slave | ||
| Ofeibea Quist-Arcton | August 4, 1958 | ||
| Ofir Drori | April 26, 1976 | ||
| Ofra Haza | Israeli Musician | November 19, 1957 | February 23, 2000 |
| Ofra Strauss | Israeli Businesswoman | August 22, 1960 | |
| Og Mandino | American Author | December 12, 1923 | September 3, 1996 |
| Ogden Nash | American Poet | August 19, 1902 | May 19, 1971 |
| Ogyu Sorai | Philosopher | March 21, 1666 | February 28, 1728 |
| Oh Eun-young | 1985 |