Born in Fife, Gilbert was the grandson of the sculptor Sir Alfred Gilbert, who made the famous Eros statue in Piccadilly Circus. Stephen Gilbert studied at the Slade School of Art from 1929-32 and exhibited regularly in London in the 1930s. He moved to Paris in 1937 but the outbreak of World War II prompted his relocation to Ireland, where he became associated with The White Stag group of refugee artists. In 1946 he returned to Paris where he remained for the rest of his long life. He was involved in several avant-garde art groups, including CoBrA, but in the 1950s he became more interested in abstraction and began exploring three-dimensional form and sculpture, influenced by modernist architecture. He returned to painting in the 1980s.