Ruth Williams (1926–2005) was a baseball pitcher.

Ruth Williams may also refer to:

• Ruth J. Williams, Australian-American mathematician
• Ruth Williams (badminton) (born 1989), Jamaican badminton player
• Ruth C. Williams (1897–1962), Australian writer for children
• Ruth Margaret Williams, British mathematician
• Ruth Williams Cupp (1928–2016), American lawyer and legislator
• Ruth Williams Khama (1923–2002), First Lady of Botswana from 1966 to 1980
• Ruth Williams-Simpson (born 1949), Jamaican sprinter
• Ruth Williams, character in 1940 American film noir Babies for Sale

• Linda Ruth Williams (born 1961), professor of film studies