The Westminster Theatre was a London theatre, on Palace Street in Westminster. It was originally built as the Charlotte Chapel in 1766, which was altered and given a new frontage for use as a cinema from 1924 onwards. It finally became a theatre in 1931 after radical alterations. By the time it fell out of use in the late 20th century, it had been remodelled twice more (in 1966 and 1972) and had three storeys, a 560-seat main house and a 100-seat studio theatre.
The theatre was bought by the Westminster Memorial Trust in April 1946 as a memorial to men in Moral Re-Armament who gave their lives in World War II. The Trust held it for more than 30 years. In the 1950s and 1960s it was the base for Furndel Productions, run by actor Alan Badel and producer William Anthony Furness. A long campaign to save it from demolition by its then owners ended when a fire destroyed 75% of the building on 27 June 2002, with demolition coming soon afterwards.
In May 2009, plans for a new 314-seat theatre and a smaller cabaret stage, flats and a restaurant, all situated on the site of the original building, were given approval by Westminster City Council. The new St James Theatre opened in September 2012.
- Harley Granville Barker's Waste, 1936, directed by the author. The first full public production.
- Toussaint Louverture by C.L.R. James, 1936, directed by Peter Godfrey, starring Paul Robeson, Orlando Martins and Harry Andrews.
- Oscar Wilde's An Ideal Husband, 1943, with Martita Hunt as Mrs Cheveley
- Eden and Adelaide Phillpott's comedy Yellow Sands, from 29 March 1945, with Cedric Hardwicke as Richard Varwell
- Henry V, July 1953, Elizabethan Theatre Company, notable as the first London play ever to be directed by John Barton.
- The Duenna (music: Julian Slade; lyrics & book: Dorothy Reynolds) London production, opened 28 July 1954 and ran for 134 performances
- British Touring Shakespeare Company, Hamlet, 2002