Born in St. Ives, Cornwall, which remained his base, Lanyon had painting lessons after school from Borlase Smart throughout 1936. The following year he attended the Penzance School of Art. He also studied at the Euston Road School in 1938 where he was encouraged and taught by Ben Nicholson, Adrian Stokes and Naum Gabo. He made his first constructions 1939-40 and served with the Royal Air Force from 1940 - 1945.
His first solo show was held at the Lefevre Gallery was in 1949. He was to exhibit internationally in mixed exhibitions, including West Country Landscape, Arts Council Tour, 1953; the Redfern Gallery, 1957, and the Tate Gallery in 1963. He was founder member of the Crypt Group, 1946, exhibited with the Penwith Society in 1949 and taught at Bath Academy of Art from 1950-7. He was elected Member of the Newlyn Society, 1953, and ran the St. Peter's Loft Art School, St.Ives, with William Redgrave from 1955-60. His first solo show in New York was held in 1957.
Lanyon's work is in many public galleries, including the Tate. Retrospective at Whitworth Art Gallery, Manchester, 1978, and South Bank Centre, 1992, both with tour.