Mercury Theatre most often refers to:
Mercury Theatre (1937–1946), an independent repertory theatre company founded in New York City by Orson Welles and producer John Houseman.
Mercury Theatre may also refer to:
Theatre buildings England Mercury Theatre, Notting Hill Gate, London, 1933–1987 Mercury Theatre, Colchester, opened 1972
New Zealand Mercury Theatre, Auckland, founded 1910
Theatre companies Australia Mercury Theatre (Australia), originally St James' Hall, Sydney, later renamed by actor Peter Finch
Entertainment The Mercury Theatre on the Air, originally titled First Person Singular, a 1938 radio drama anthology series created by Orson Welles