Katharine Hepburn is a professional actress.
Katharine Houghton Hepburn ( May 12 , 1907 -- June 29 , 2003 ) was an American actress . She found a niche playing middle-aged spinsters , such as in The African Queen ( 1951 ) , a persona the public embraced . The African Queen (film) . The film stars Humphrey Bogart ( who won the Academy Award for Best Actor -- his only Oscar ) , and Katharine Hepburn with Robert Morley , Peter Bull , Walter Gotell , Richard Marner and Theodore Bikel .