His credits, many with life-long friend and collaborator Willis Hall, include satires such as That Was The Week That Was, BBC-3 and The Frost Report during the 1960s, the book for the 1975 musical The Card, Budgie, Worzel Gummidge, and Andy Capp (an adaptation of the comic strip).
His 1959 book Billy Liar was subsequently filmed by John Schlesinger with Tom Courtenay in the part of Billy. It was nominated in six categories of the 1964 BAFTA awards, including Best Screenplay, and was nominated for the Golden Lion at the Venice Film Festival in 1963; in the early 1970s a sitcom based on the character was quite popular and ran to 25 episodes—a respectable run for a British sitcom, although it has seldom been seen since.
Waterhouse's first screenplay was the film Whistle Down the Wind (1961). Without receiving screen credit, Waterhouse and Hall did extensive rewrites on the original script for Alfred Hitchcock's Torn Curtain (1966). Waterhouse is also the author of the play Jeffrey Bernard is Unwell (1989; Old Vic premiere, 1999), based on the life of journalist Jeffrey Bernard.
His career began at the Yorkshire Evening Post and he also wrote regularly for Punch, the Daily Mirror, and for the Daily Mail. His extended style book for the Daily Mirror, Waterhouse On Newspaper Style, is regarded as a classic textbook for modern journalism. This was followed by a pocket book on English usage intended for a wider audience entitled English Our English (And How To Sing It).
He fought long crusades to highlight what he perceived to be a decline in the standards of modern English; for example, he founded the Association for the Abolition of the Aberrant Apostrophe, whose members attempt to stem the tide of such solecisms as "pound's of apple's and orange's" in greengrocers' shops.
In February 2004 he was voted Britain's most admired contemporary columnist by the British Journalism Review.
On 4 September 2009, a statement released by his family announced that Waterhouse had died quietly in his sleep at his home in London; he was 80.
Keith Spencer Waterhouse (1929-02-06 – 2009-09-04) was an English novelist, playwright, screenwriter and journalist. His first novel, Billy Liar, has been adapted into a play, a musical, a film, and a television sitcom.