Wilson was born in Sale, Cheshire, England, and was educated at Harrow School. In 1942 he won a State Scholarship for a wartime course at SOAS and was assigned to study Japanese. He was thus one of the so-called 'Dulwich Boys' who studied at SOAS and boarded at Dulwich College. While there he put together a satirical review titled 'A Matter of Course' based on his experiences on the Japanese course. He was one of the few not to complete the course and he subsequently served in the Royal Army Ordnance Corps in Great Britain, Egypt and Iraq. After the war he went to Oriel College, Oxford and while a student wrote revues for the Oxford University Experimental Theatre Club and then attended the Old Vic Theatre School on a production course.
Most of his work for the stage was material for revues, such as Hermione Gingold's Slings and Arrows, Laurier Lister's Oranges and Lemons, and See You Later, starring such performers as Peter Cook. He wrote the book, music and lyrics for The Boy Friend for the Players' Theatre in 1953. Its success resulted in a longer version being produced in the West End at Wyndhams Theatre. After its opening in January 1954, over 2,000 performances were put on there. It opened on Broadway in 1954, at the Royale Theater, and introduced Julie Andrews in her Broadway debut. The show ran on Broadway for over 480 performances.
Wilson wrote the musical Valmouth in 1958, based on a Ronald Firbank novel set in a seaside resort. In 1964 he wrote Divorce Me, Darling!, a sequel to The Boy Friend. His last work was a version of Aladdin (1979) for the Lyric Theatre, Hammersmith.
His autobiography, published in 1975, is titled I Could Be Happy.
Sandy Wilson died in Taunton, England in 2014, aged 90. His longtime partner was Chak Yui. Wilson was a member of the Labour Party and contributed to the Elizabethan magazine during his years of greatest fame.
In 1999, Wilson donated his papers to the Harry Ransom Center. The papers include produced and unproduced plays, mostly musicals but also plays for stage and TV, as well as drafts of Wilson's published and unpublished works including an autobiography, illustrated book, novels, articles, and short stories, along with correspondence.
- Stevens, Christopher (2010). Born Brilliant: The Life of Kenneth Williams. John Murray. pp. 364/5. ISBN 1-84854-195-3.
- Colin Larkin, ed. (2002). The Virgin Encyclopedia of Fifties Music (Third ed.). Virgin Books. p. 502. ISBN 1-85227-937-0.
- Sandy Wilson, I Could be Happy: An Autobiography (London: Joseph, 1975), p. 75.
- Peter Kornicki, Eavesdropping on the Emperor: Interrogators and Codebreakers in Britain's War with Japan (London: Hurst & Co., 2021), p. 57.
- Slotnik, Daniel E. (31 August 2014). "Sandy Wilson, Composer and Writer of 'The Boy Friend,' Dies at 90". The New York Times. Retrieved 29 October 2019.
- Freedland, Michael and Michael Coveney. "Sandy Wilson obituary", The Guardian, 27 August 2014, accessed 10 November 2017
- Beck, Andy and Fisher, Brian. Broadway for Two, Alfred Music Publishing, 2007, ISBN 0-7390-4477-X, p. 82
- Freedland, Michael; Coveney, Michael (27 August 2014). "Sandy Wilson obituary". Theguardian.com. Retrieved 29 October 2019.
- "Sandy Wilson:A Preliminary Inventory of His Papers at the Harry Ransom Humanities Research Center", Utexas.edu, retrieved 9 March 2010