Born in Middlesex, Hilton studied at the Slade School from 1929-1931 under Henry Tonks, winning a Slade Scholarship in 1931, which he did not take up. For two and a half years in the early 1930s he studied in Paris at the Academie Ranson under Bissiere and had his first solo exhibition at the Bloomsbury Gallery in 1936. He joined the Commandos in 1940 and was captured in 1942, becoming a POW until 1945.
After the war, he became a schoolteacher, and in the early 1950s, encouraged by a member of the Cobra Group, Hilton turned to Abstract Art. In 1951 he was invited to participate in Abstract Paintings, Sculptures and Mobiles, the first entirely abstract post-war exhibition in England, at the AIA Gallery in London. In 1952 he held his first post-war solo exhibition at Gimpel Fils. Between 1954 - 1956 Hilton taught at the Central School of Art & Design, during which time he began making trips to Cornwall, staying first with Patrick Heron. He moved permanently to Botallack, Cornwall, in 1965 and became an important part of the St Ives group.
A major retrospective was held at the Hayward Gallery, London in 1993, followed by a drawing survey at the Tate Gallery St Ives in 1997. His work is in numerous international public collections, including the Tate Gallery, the Victoria and Albert Museum, the British Museum, and the Fogg Art Gallery at Harvard.
