His work in the satirical revue Beyond the Fringe at the 1960 Edinburgh Festival brought him instant fame and later a Special Tony Award.

He remained at the university for several years, working as a junior lecturer of Medieval History at Magdalen College,[3] before deciding, in 1960, that he was not suited to being an academic.

In August 1960, Bennett – along with Dudley Moore, Jonathan Miller and Peter Cook – gained fame after an appearance at the Edinburgh Festival in the satirical revue Beyond the Fringe, with the show continuing in London and New York.

[4] Bennett's first stage play, Forty Years On, directed by Patrick Garland and starring John Gielgud, was produced in 1968.

Many television, stage and radio plays followed, with screenplays, short stories, novellas, a large body of non-fictional prose, and broadcasting and many appearances as an actor.

"[5] Bennett's many works for television include his first play for the medium, A Day Out in 1972, A Little Outing in 1977, Intensive Care in 1982, An Englishman Abroad in 1983, and A Question of Attribution in 1991.

[9] The West End show took more than £1 million in advance ticket sales[10] and even extended the run to cope with demand.

Entitled The Madness of King George (1994), the film received four Academy Award nominations: for Bennett's writing and the performances of Nigel Hawthorne and Helen Mirren.

In his 2005 prose collection Untold Stories, Bennett wrote of the mental illness that his mother and other family members suffered.

At the National Theatre in late 2009 Nicholas Hytner directed Bennett's play The Habit of Art, about the relationship between the poet W. H. Auden and the composer Benjamin Britten.

[15] In December that year, Cocktail Sticks, an autobiographical play by Bennett, premièred at the National Theatre as part of a double bill with the monologue Hymn.

[17] In July 2018, Allelujah!, a comic drama by Bennett about a National Health Service hospital threatened with closure, opened at London's Bridge Theatre to critical acclaim.

[18] Bennett lived for 40 years on Gloucester Crescent in Camden Town, London, and in 2006 moved a few minutes' walk away to Primrose Hill with his partner Rupert Thomas, the former editor of The World of Interiors magazine.

Previously Bennett had referred to questions about his sexuality as like asking a man who has just crawled across the Sahara desert to choose between Perrier or Malvern mineral water.

"[29] Following the death of Jonathan Miller in 2019, Bennett became the only surviving member of the original Beyond the Fringe quartet which had also included Peter Cook and Dudley Moore.

In 1998 he refused an honorary doctorate from Oxford University, in protest at its acceptance of funding for a chair from press baron Rupert Murdoch.