Born in Boston, Massachusetts, Keith grew up in Chicago. He was educated at the Francis Parker School there and played Hamlet in a school production at age 16.^[1]

Keith was a veteran character actor of the stage, and appeared in a variety of colorful roles in silent features of the 1920s.

In 1919, as Keith Ross, he acted with the Copley Repertory Theatre in Boston.^[2] On Broadway, as Ian Keith, he performed in The Andersonville Trial (1959), Edwin Booth (1958), Saint Joan (1956), Touchstone (1953), The Leading Lady (1948), A Woman's a Fool - to Be Clever (1938), Robin Landing (1937), King Richard II (1937), Best Sellers (1933), Hangman's Whip (1933), Firebird (1932), Queen Bee (1929), The Command Performance (1928), The Master of the Inn (1925), Laugh, Clown, Laugh! (1923), As You Like It (1923), The Czarina (1922), and The Silver Fox (1921).^[3]

He played John Wilkes Booth in D. W. Griffith's first sound film, Abraham Lincoln. Keith had a major role as a gambler in director Raoul Walsh's 1930 widescreen western The Big Trail starring John Wayne. In 1932, Cecil B. DeMille cast him in The Sign of the Cross. This established him as a dependable supporting player, and he went on to play dozens of roles—including Octavian (Augustus) in Cleopatra—in major and minor screen fare for the next three decades.

He became one of DeMille's favorites, appearing in many of the producer's epic films. He portrayed Count de Rochefort in both the 1935 version and the 1948 remake of The Three Musketeers. In the 1940s he became even busier, working primarily in "B" features and westerns and alternating between playing good guys (a chief of detectives in The Payoff, a friendly hypnotist in Mr. Hex, a blowhard politician in She Gets Her Man) and bad guys (a murder suspect in The Chinese Cat, a crooked lawyer in Bowery Champs, a swindler in Singing on the Trail). He appeared in a supporting role to Tyrone Power in Nightmare Alley (1947) as a former vaudevillian turned carny who has succumbed to alcoholism. He also had a definite flair for comedy, and his florid portrayal of the comic-strip ham actor "Vitamin Flintheart" in Dick Tracy vs. Cueball was so amusing that he repeated the role in two more films.

He played tough-guy military roles, such as Admiral Burns in Robert Gordon's sci-fi epic, It Came From Beneath the Sea (1955).

He also appeared on many television episodes in the 1950s, including starring in the premiere episode of The Nash Airflyte Theater in 1950.^[4] In 1955, he was seen on screen in his only Shakespeare role, when he made a cameo appearance as the Ghost opposite Richard Burton's Hamlet in a sequence from the Edwin Booth biopic Prince of Players. Cecil B. DeMille brought him back to the big screen for The Ten Commandments (1956); Keith played Ramses I.

Keith played Emmett Dayton in the radio soap opera Girl Alone.^[5]

Keith died in Medical Arts Hospital in New York on March 26, 1960,^[6] and was cremated in Hartsdale, New York.^[7]

• Blanche Yurka^[8] (1922 - 1926)
• Ethel Clayton^[7] (1928 - 1931)
• Fern Andra^[7] (m. in 1932 and again in 1934, when the legality of the first ceremony was questioned; divorced; in 1938 Andra married again)
• Hildegarde Pabst^[7] (1936 - 1960)^[9]

• Ian Keith at the Internet Broadway Database  
• Ian Keith at IMDb
• Ian Keith photo gallery at New York City Public Library