Wilson was born in Bexhill, Sussex, England, to an English father and South African mother. He was educated at Westminster School and Merton College, Oxford, and in 1937 became a librarian in the British Museum's Department of Printed Books, working on the new General Catalogue. During World War II, he worked in the Naval section Hut 8 at the code-breaking establishment, Bletchley Park, translating Italian Naval codes. A wearer of large, brightly-coloured bow-ties, he was one of the "famous homosexuals" at Bletchley. The work situation was stressful and led to a nervous breakdown, for which he was treated by Rolf-Werner Kosterlitz. He returned to the Museum after the end of the War, and it was there that he met Tony Garrett (born 1929), who was to be his companion for the rest of his life.

Wilson's first publication was a collection of short stories, The Wrong Set (1949), followed quickly by the daring novel Hemlock and After, which was a great success, prompting invitations to lecture in Europe. He worked as a reviewer, and in 1955 he resigned from the British Museum to write full-time (although his financial situation did not justify doing so) and moved to Suffolk. From 1957 he gave lectures further afield, in Japan, Switzerland, Australia, and the USA. He was awarded a CBE in 1968, and received many literary honours in succeeding years. A knighthood was granted in 1980, prompting many hostile comments in the press. Remaining years were spent battling ill health.

His writing, which has a strongly satirical vein, expresses his concern with preserving a liberal humanistic outlook in the face of fashionable doctrinaire temptations. Several of his works were adapted for television. He jointly helped to establish the now renowned creative writing course at the University of East Anglia.

Novels

• Hemlock and After (1952)
• Anglo-Saxon Attitudes (1956)
• The Middle Age of Mrs Eliot (1958)
• The Old Men at the Zoo (1961)
• Late Call (1964)
• No Laughing Matter (1967)
• As If By Magic (1973)
• Setting the World on Fire (1980)

Short story collections

• The Wrong Set (1949)
• Such Darling Dodos (1950)
• A Bit Off the Map (1957)

Play

• The Mulberry Bush (1955)

Others

• a Scrapbook of the Twenties (1953)
• The Wild Garden or Speaking of Writing (1963)
• The World of Charles Dickens (1970)
• The Naughty Nineties (1976)
• The Strange Ride of Rudyard Kipling: His Life and Works (1977)
• Diversity and Depth in Fiction: Selected Critical Writings of Angus Wilson (1983)
• Reflections In A Writer's Eye: travel pieces by Angus Wilson (1986)