Born in Cornwall, educated at King's College, Taunton. At 19 he joined RNVR as a Naval Officer taking part in D-Day, Sword Beach. He read modern History at Lincoln College Oxford 1948-52 also the Ruskin School of Drawing. He studied painting at the Royal College of Art 1952-55, and became Senior Tutor at the RCA Painting School 1976-80. His first one-man exhibition was at Colette Allendy Galerie, Paris 1959.
John Barnicoat was described in 'Exhibition Road. Painters at the Royal College of Art.' Edited by Paul Huxley (1988), as a 'gifted painter and highly esteemed teacher and administrator and as widely regarded as one of the most thoughtful and influential voices in art education'.
Barnicoat was Head of Falmouth School of Art 1972-76; Head of Chelsea School of Art 1980-89. He wrote Posters a Concise History (Thames & Hudson 1972) translated into many languages and organised and curated exhibitions in the UK and Russia on the art of the poster.
From a young boy in Cornwall, during the war and later, he made pen and ink drawings, and was a painter of oils and works on paper using tempera, conté and acrylic. He showed continuously with one-man shows at Galerie Colette Allendy Paris (1959) Molton Gallery (Annely Juda) (1962) one-man exhibitions at the Taranman Gallery (1977-83) including the London Group (1955-1996); and his work is represented in both government and private collections.