Anne Clarissa Eden, Dowager Countess of Avon (née Spencer-Churchill; 28 June 1920), is the widow of Anthony Eden, 1st Earl of Avon (1897–1977), who was British Prime Minister from 1955 to 1957. She married Eden in 1952, becoming Lady Eden in 1954 when he was made a Knight of the Garter, and then becoming Countess of Avon in 1961 on her husband's elevation to the peerage. Her memoir, sub-titled From Churchill to Eden, was published in 2007 under the name of Clarissa Eden.