Gladys Constance Cooper (December 18, 1888 - November 17, 1971) was an English actress, created a Dame (DBE) for her services to the theatre. She was born in London and made her stage début in 1905. It was not until 1922, however, that she found major success, in Pinero's The Second Mrs. Tanqueray.

She found success in Hollywood in a variety of character roles and was most frequently cast as a disapproving, aristocratic society woman. She was nominated three times for an Academy Award for Best Supporting Actress for her performances as Bette Davis's pathologically repressive mother in Now, Voyager; as a skeptical nun in The Song of Bernadette; and as Mrs Higgins in My Fair Lady. Gladys Cooper's daughter married the actor, Robert Hardy.

An old theater anecdote recalls that in 1928, she appeared in the play Excelsior in which her sister Doris, a neophyte, was given a bit part. On opening night, Doris was reduced to tears backstage after her first appearance, which was greeted by a low hiss from the audience. "Oh no, dear," a friend reassured her. "They're just all whispering to each other, "She's Doris Cooper. She's Gladys Cooper's sister. Gladys Cooper's sister."