King was a native of Okmulgee in east central Oklahoma. He studied acting at the St Louis School of Theater, from which he graduated in 1941, before enlisting in the United States Navy during World War II, in which he served in the South Pacific campaign from 1943 to 1945.

King married June Ellen Roth in 1948. The couple had their first child the next year.

King made his small screen debut in 1949 as Midshipman Bascomb in the television series, Captain Video and His Video Rangers.

King was cast in numerous westerns and is particularly known for his role in the 1951 film adaptation of Tennessee Williams’ A Streetcar Named Desire, starring Vivien Leigh (whom his character kisses). Prior to that, he had appeared in the original stage production, a performance which was lauded by drama critic Harold Hobson. In 1958 King appeared as The Kiowa Kid/Nevada Jones on the TV western Cheyenne in the episode “Ghost of the Cimarron.”. In 1957 King starred as Joe Digger, a falsely accused horse thief who was hung but saved, then hung again after he killed one of his original hangers in the Gunsmoke episode “Born To Hang”. King also appeared in eleven episodes of the television series Wanted Dead or Alive starring Steve McQueen, often playing a young sidekick named Jason Nichols.

In 1974, he played U.S. Senator Richard B. Russell Jr. of Georgia in the TV movie The Missiles of October, a dramatization of the Cuban Missile Crisis of 1962.

He died in Canoga Park, Los Angeles on 25 November 2018 at the age of 95.