Margaret Leighton, CBE (26 February 1922 – 13 January 1976) was an English actress. Her film appearances included The Winslow Boy (1948), Under Capricorn (1949), Calling Bulldog Drummond (1951), Carrington V.C. (1955) and The Best Man (1964). For The Go-Between (1971), she won the BAFTA Award for Best Actress in a Supporting Role and was nominated for the Academy Award for Best Supporting Actress.

Leighton began her career on stage in 1938, before joining the Old Vic and making her Broadway debut in 1946. A four-time Tony Award nominee, she twice won the Tony Award for Best Actress in a Play: for the original Broadway productions of Separate Tables (1957) and The Night of the Iguana (1962). She also won an Emmy Award for a 1970 television version of Hamlet.