Anne Clarissa Eden, Countess of Avon (; born 28 June 1920) is the widow of Anthony Eden, 1st Earl of Avon (1897–1977), who was Prime Minister of the United Kingdom from 1955 to 1957. She married Eden in 1952, becoming Lady Eden in 1954 when he was made a Knight of the Garter, before becoming Countess of Avon in 1961 on her husband's being created an earl. She is also the niece of Prime Minister Winston Churchill. Her 2007 memoir was sub-titled "From Churchill to Eden".