Sinclair directed the film, now regarded as a classic, of Under Milk Wood. His book The Better Half: The Emancipation of the American Woman won the Somerset Maugham Prize in 1967. His biographies have covered a wide variety of famous people: Che Guevara, Dylan Thomas, Jack London, John Ford, J Pierpont Morgan and Francis Bacon. Sinclair is married to the writer and socialite Sonia Melchett.
He was elected a Fellow of the Royal Society of Literature in 1972.
Andrew Sinclair married firstly Marianne Alexandre in 1960 (later divorced) and had one son Timon Alexandre Sinclair; secondly Miranda Seymour, daughter of George Fitzroy Seymour (cadet branch of Marquess of Hertford and Duke of Somerset of Thrumpton Hall) and Rosemary Nest Scott-Ellis, daughter of Thomas Evelyn Scott-Ellis, 8th Baron Howard de Walden (1880–1946), on 17 October 1972 (marriage dissolved 6 June 1984) and had one son Merlin George Sinclair; thirdly Sonia Melchett, widow of British Steel Corporation Chairman Julian Mond, 3rd Baron Melchett, on 25 July 1984, without issue.
Through his third marriage, Sinclair is the stepfather of Peter Mond, 4th Baron Melchett, politician and environmentalist, and Kerena Ann Mond and Pandora Mond.
- Prohibition: The Era of Excess (1962)
- The Better Half: The Emancipation of the American Woman (1965)
- A Concise History of the United States (1967, revised and updated 1999)
- Viva Che!: The Strange Death and Life of Che Guevara (1968, re-released 2006, Sutton ISBN 0-7509-4310-6)
- The Last of the Best: The Aristocracy of Europe in the Twentieth Century (1969)
- Guevara (Fontana Modern Masters, 1970)
- Dylan Thomas: Poet of His People (1975)
- Jack: A Biography of Jack London (1977)
- John Ford: a Biography (1979)
- Corsair: The Life of J Pierpont Morgan (1981)
- The Other Victoria (1985)
- The Red and the Blue: Cambridge, Treason and Intelligence (1986)
- War Like a Wasp: The Lost decade of the Forties (1989)
- Francis Bacon: His Life and Violent Times (1993)
- Arts and Cultures: The History of the Fifty Years of the Arts Council in Great Britain (1996)
- Great Britain (1996)
- Death by Fame: A Life of Elisabeth Empress of Austria (1998)
- Dylan the Bard: A Life of Dylan Thomas (1999, Constable; 2003, Robinson ISBN 1-84119-741-6)
- The Breaking of Bumbo. London, Faber, and New York, Simon and Schuster, 1959; Penguin edition 1961 (cover by George Adamson).
- My Friend Judas. London, Faber, 1959; New York, Simon and Schuster, 1961.
- The Project. London, Faber, and New York, Simon and Schuster, 1960.
- The Hallelujah Bum. London, Faber, 1963; as The Paradise Bum, New York, Atheneum, 1963.
- The Raker. London, Cape, and New York, Atheneum, 1964.
- Gog. London, Weidenfeld and Nicolson, and New York, Macmillan, 1967.
- Magog. London, Weidenfeld and Nicolson, and New York, Harper, 1972.
- The Surrey Cat. London, Joseph, 1976; as Cat, London, Sphere, 1977.
- A Patriot for Hire. London, Joseph, 1978.
- The Facts in the Case of E.A. Poe. London, Weidenfeld and Nicolson, 1979; New York, Holt Rinehart, 1980.
- Beau Bumbo. London, Weidenfeld and Nicolson, 1985.
- King Ludd. London, Hodder and Stoughton, 1988.
- The Far Corners of the Earth. London, Hodder and Stoughton, 1991.
- The Strength of the Hills. London, Hodder and Stoughton, 1992.
- Uncollected short stories
- "To Kill a Loris," in Texas Quarterly (Austin), Autumn 1961.
- "A Head for Monsieur Dimanche," in Atlantic (Boston), September 1962.
- "The Atomic Band," in Transatlantic Review 21 (London), Summer 1966.
- "Twin," in The Best of Granta. London, Secker and Warburg, 1967.
- Under Milk Wood (1972) Director. Starring Richard Burton, Elizabeth Taylor, Peter O'Toole.
- Blue Blood (1973)
- Dylan on Dylan (2002, Timon Films)
- This article incorporates a fiction bibliography from the corresponding Italian Wikipedia article as of 20 November 2010.
- England's Greatest Tourist and Tourist Attraction: Andrew Sinclair's Gog, Magog (1967, 1972), Peter Wolfe. In Old lines, new forces: essays on the contemporary British novel, 1960–1970, Robert K Morris, Fairleigh Dickinson University Press, 1976.