Louis Burt Mayer (July 4, 1885–October 29, 1957) was an early film producer.

Born Eliezer Meir in Minsk, Russia, (now Belarus), his family immigrated to Saint John, New Brunswick, Canada when he was still very young and Mayer attended school there.

On November 28, 1907 in Haverhill, Massachusetts, Mayer, then a scrap-metal dealer, opened his first movie theater. Within a few years he had the largest theater chain in New England, and in 1917 he founded his own production company, Louis B. Mayer Pictures , which eventually became part of Metro-Goldwyn-Mayer.

As head of production for the new MGM, Louis B. Mayer made it the most successful motion picture studio in the world, and was the only one to pay dividends throughout the Great Depression of the 1930s. Under Mayer, MGM produced a litany of successful films and the greatest stars, including Clark Gable, Spencer Tracy, Katharine Hepburn, Lon Chaney, Joan Crawford, Jean Harlow, Judy Garland and many others.

Mayer had two daughters from his first marriage to Margaret Shenberg. Daughter Irene Gladys Mayer, married famed film producer David O. Selznick and second daughter Edith (Edie) Mayer was married to producer William Goetz who became President of Universal Pictures.

Active in Republican Party politics, Mayer served as the vice-chair of the California Republican Party from 1931 to 1932 and its state chair between 1932 and 1933.

Louis B. Mayer died on October 29, 1957 and was interred in the Home of Peace Cemetery in East Los Angeles, California.

See also: Other Canadian pioneers in early Hollywood