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.