Mark Herron (8 July 1928 – 13 January 1996) was an American actor best known as the fourth husband of singer and actress Judy Garland. They were married on 14 November 1965 in Las Vegas, but they separated after 5 months of marriage apparently due to his homosexuality. Seventeen months later, Garland was granted a divorce after testifying that Herron had beaten her. He said he had "only hit her in self defense." He appeared in films such as Federico Fellini's 8½ and Eye of the Cat.

Fans of the cable TV show Mystery Science Theater 3000 may recall his performance in the film Girl in Gold Boots, in which he portrayed the greasy nightclub owner Leo McCabe.

Gerald Clarke, in his biography of Garland, Get Happy (2000) and in an interview about the book, reported that Herron had an affair with Tallulah Bankhead prior to meeting Garland.

Garland put Herron to work as producer of her two London Palladium concerts with her daughter Liza Minnelli in 1964 as well as some personal appearances in Canada in 1965.

Aside from providing biographer Gerold Frank information for his biography titled Judy (1975), Herron remained silent on the topic of Garland. He continued acting, often appearing in summer stock productions.

Herron had a long-lasting relationship with fellow actor Henry Brandon, which was only briefly interrupted by his marriage to Garland. The two men remained together until Brandon's death in 1990.

Herron died of cancer in 1996, aged 67.