Born Jack Carlton Moore in Chicago, Illinois, Moore became a circus acrobat by age 8 and appeared at the Century of Progress exposition in Chicago in 1934 with a trapeze act.As a young man, Moore worked successfully as a John Robert Powers model. Moving to Hollywood in the late 1930s, he worked as a stunt man and bit player between modeling jobs. According to his autobiography, around 1940 Hollywood producer Edward Small persuaded him to adopt the stage name “Clayton” Moore. He was an occasional player in B westerns and the lead in four Republic Studio cliffhangers, and two for Columbia. Moore served in the U.S. Army Air Forces during World War II and made training films (Target–Invisible, etc.) with the First Motion Picture Unit.

Moore’s career advanced in 1949, when George Trendle spotted him in Ghost of Zorro. As creator/producer of The Lone Ranger radio show (with writer Fran Striker), Trendle was about to launch the television version. Moore landed the role.Moore trained his voice to sound like the radio version of The Lone Ranger, which had then been on the air since 1933, and succeeded in lowering his already distinctive baritone even further. With the first notes of Rossini’s “William Tell Overture” and actor Gerald Mohr’s “Return with us now to those thrilling days of yesteryear … ,” Moore and co-star Jay Silverheels, in the role of Tonto, made television history as the stars of the first Western written specifically for that medium. The Lone Ranger soon became the highest-rated program to that point on the fledgling ABC network and its first true hit, earning an Emmy nomination in 1950. Moore starred in 169 episodes of the television show.

After two successful years presenting a new episode every week, 52 weeks a year, Moore had a pay dispute and left the series. As “Clay Moore,” he made a few more westerns and serials, sometimes playing the villain. Moore was replaced for a time by actor John Hart. Eventually the show’s producers came to terms and rehired Moore. He stayed with the program until it ended first-run production in 1957. He and Jay Silverheels also starred in two feature-length Lone Ranger motion pictures. Moore appeared in other series too, including a role in the 1952 episode “Snake River Trapper” of Bill Williams’s syndicated western, The Adventures of Kit Carson.After completion of the second feature, The Lone Ranger and the Lost City of Gold in 1958, Moore embarked on what would be 40 years of personal appearances, TV guest spots, and classic commercials as the legendary masked man. Silverheels joined him for occasional appearances during the early 1960s. Throughout his career, Moore expressed respect and love for Silverheels.