Born at Denham, Buckinghamshire, the son of painters William NICHOLSON and Mabel PRYDE. Nicholson met Paul Nash at the Slade (1910-11) but, was otherwise without formal training. He travelled in France, Italy, Spain and California between 1911 and 1918, but became serious about painting only after 1920 when he married artist Winifred Roberts, and shortly thereafter began abstract paintings influenced by Synthetic Cubism. His association with Barbara HEPWORTH and Henry MOORE dates from 1931 when he was living in London.

With Hepworth he visited in France and met Arp, Brancusi, Braque and Picasso. Later he was encouraged to join Abstraction-Creation and met Piet Mondrian. He exhibited with the Seven and Five Society.Nicholson married Barbara HEPWORTH in 1934, and was co-editor of Circle, the constructivist art magazine in 1937.

The couple moved to Carbis Bay, Cornwall, at the outbreak of War in 1939. In Cornwall he returned to painting landscapes, but added colour to his abstract reliefs previously devised in his constructivist period. Persuaded to join STISA by Borlase SMART in 1944, Nicholson tried to influence the direction of STISA after Smart's death, and was instrumental behind-the-scenes in the split of STISA, being a founder Member of the Penwith Society of Arts. Though not universally liked, he was a great influence on many young artists in St Ives, including Wilhelmina BARNS-GRAHAM, George Peter LANYON and Sven BERLIN. His marriage to Barbara HEPWORTH was dissolved in 1951 and he left St Ives in 1958.