A graduate of Worcester Academy in 1922, Starrett went on to study at Dartmouth College. While on the Darmouth football team, he was hired to play a football extra in the 1926 film The Quarterback. In 1930 he played the romantic lead in Fast and Loose, which also featured Miriam Hopkins, Carole Lombard and Frank Morgan. After that, he was very active for the next two years but his roles were unremarkable. In 1933 he was featured in Our Betters and helped organize the Screen Actors Guild, and in 1936 signed with Columbia Pictures to become one of the top ten western stars, starring in 115 movies the following 16 years. After playing assorted sheriff and rangers roles, Starrett gained fame for his role as the Durango Kid. The first film in which he played his famous alter-ego character was known as The Durango Kid, which was released in 1940, but for some reason, Columbia did not see fit to continue with the series at that time. The character was revived in 1944 and lasted through 1952. Dub Taylor, as "Cannonball", worked with Starrett until 1946. At that time, Smiley Burnette, who had been a very popular sidekick to Gene Autry, was brought in to replace Taylor. Burnette, appropriately enough, played a character called Smiley Burnette. The Durango Kid films combined vigorous action sequences – often with speeded up camera work and spectacular stunts performed by Jock Mahoney – and western music. Each film featured a singing group, and many gave free rein to Burnette's singing and playing.
Starrett, who was independently wealthy, ended his acting career at age 48 when the Durango Kid series ceased production. He once told the Dartmouth alumni magazine that most of his California neighbors thought he was a retired banker.
Starrett died in Borrego Springs, California, six days short of his 83rd birthday.
NOTE:Most of the Durango Kid movies have showed up on the Encore Westerns channel and not The Movie Channel. Around twenty have been screened thus far; Columbia/Sony have released two (thus far) on DVD: Bonanza Town and Blazing Across the Pecos, both superior vehicles and both in great quality.