Madeleine Sherwood, born Madeleine Thornton, was a Canadian actress known for her work in theater, film, and television. Her career was inextricably linked to playwright Tennessee Williams, as she originated on Broadway the roles of Mae Pollitt in *Cat on a Hot Tin Roof* (1955) and Miss Lucy in *Sweet Bird of Youth* (1959), a performance that earned her a Tony Award nomination. She reprised both characters in the acclaimed film adaptations. To wider television audiences, she is best known for her role as Reverend Mother Superior Placido in the popular series *The Flying Nun* (1967–1970). A member of the Actors Studio under Lee Strasberg, her career was partially hindered by her inclusion on the Hollywood blacklist during the McCarthy era due to her civil rights activism. Her other film credits include *Hurry Sundown* and *The Crucible*.