| | People in Born Today |
| | Last | Honor | First | Middle | Nationality | Occupation | Born | Died | BC | Sex | RealName | #Pix |
| | Oates | John | US | singer | 04/07/1949 | M | 1 |
| | Oates | Joyce | Carol | US | writer | 06/16/1938 | F | 2 |
| | Oates | Lawrence | Edward | English | explorer | 03/17/1880 | 03/17/1912 | M |
| | O'Brien | Conan | US | tv person | 04/18/1963 | M | 1 |
| | O'Brien | Edna | Irish | writer | 12/15/1932 | F | 1 |
| | O'Brien | Flann | Irish | writer | 10/05/1911 | 04/01/1966 | M | 1 |
| | O'Brien | Margaret | US | actor | 01/15/1937 | F | 2 |
| | O'Casey | Sean | Irish | writer | 03/30/1880 | 09/18/1964 | M |
| | O'Connor | Carroll | US | actor | 08/02/1924 | 06/21/2001 | M | 1 |
| | O'Connor | Donald | US | entertainer | 08/28/1925 | 09/27/2003 | M | 1 |
| | O'Connor | Flannery | Irish | writer | 03/25/1925 | 08/03/1964 | F | 1 |
| | O'Connor | Sandra | Day | US | Supreme Court | 03/26/1930 | F | 1 |
| | O'Connor | Sinead | Irish | singer | 12/08/1966 | F | 1 |
| | Odets | Clifford | US | writer | 07/18/1906 | 08/18/1963 | M |
| | O'Donnell | Chris | US | actor | 06/26/1970 | M | 1 |
| | O'Donnell | Rosie | US | actor | 03/21/1962 | F | 1 |
| | O'Donoghue | Michael | US | writer actor | 01/05/1940 | 11/08/1994 | M | 1 |
| | O'Dowd | Boy | George | English | singer | 06/14/1961 | M | 1 |
| | Ogden | Howard | M |
| | Ogilvy | David | English | ad exec | 06/23/1911 | 07/21/1999 | M |
| | Oh | Sandra | Korean-Canadian | actor | 01/01/1971 | F | 2 |
| | O'Hair | Madalyn | Murray | US | atheist | 04/13/1919 | 09/29/1995 | F |
| | O'Hara | John | US | writer | 01/31/1905 | 04/11/1970 | M |
| | O'Hartigan | Margaret | Deirdre | US | writer, transsexual | F |
| | O'Keefe | John | Irish | playwright | ??/??/1747 | ??/??/1833 | M |
| | O'Keeffe | Georgia | US | artist | 11/15/1887 | 03/06/1986 | F | 2 |
| | Oldman | Gary | English | actor | 03/21/1958 | M | 1 |
| | Olinghouse | Lane | M |
| | Oliphant | Margaret | Scottish | writer | 04/04/1828 | 06/25/1897 | F |
| | Oliver | Freddie | M |
| | Oliver | Gene | US | baseball player | 03/22/1935 | M | 1 |
| | Olivier | Sir | Laurence | English | movie actor | 05/22/1907 | 07/11/1989 | M | 1 |
| | Olsen | Tillie | US | writer | 01/14/1912 | 01/01/2007 | F |
| | Olson | Geoff | M |
| | Olson | Ken | US | DEC founder | 02/20/1926 | M |
| | Olson | Nancy | US | actor | 07/14/1928 | F | 1 |
| | O'Malley | Austin | US | humorist | 10/01/1858 | M |
| | Onassis | Aristotle | Greek | zillionaire | 01/15/1906 | 03/15/1975 | M | 1 |
| | Onassis | Christina | Greek | rich girl | 12/11/1950 | 11/19/1988 | F | 1 |
| | O'Neal | Alexander | US | singer | 11/14/1953 | M |
| | O'Neal | Shaquille | US | basketball player | 03/06/1972 | M | 1 |
| | O'Neill | Eugene | US | writer | 10/16/1888 | 11/27/1953 | M | 1 |
| | O'Neill | Thomas | P. "Tip" | US | speaker of the House | 12/09/1912 | 01/05/1994 | M | 1 |
| | Friday, September 28, 2007 | Page 1 of 2 |