Eileen Forrester Agar (1899–1991) was a British artist associated with the Surrealist movement.
She was born in Buenos Aires to a Scottish father and an American mother. The family moved to London in 1911. In 1924 she studied with Leon Underwood (1890–1975), and she attended the Slade School of Fine Art, London, from 1925 to 1926; she also studied art in Paris from 1928 to 1930. She was a member of the London group from 1933, and her work was selected by Roland Penrose and Herbert Read for the International Surrealist Exhibition at the New Burlington Galleries, London, in 1936. Agar exhibited with the Surrealists both in England and abroad. From 1936 she experimented with automatic techniques and new materials, taking photographs and making collages and objects, for example The Angel of Anarchy (fabric over plaster and mixed media, 1936–40; London, Tate). By the 1960s she was producing Tachist paintings with Surrealist elements.
She married the Hungarian writer Josef Bard in 1940.