Born on November 12, 1920 at Gracemont, Oklahoma to Maurice Greely Harrison and Azalee Belle McAdams. He moved to Plainview, Texas as a child (1930 US Census Hale County, Texas). Carson became an accomplished rodeo rider in his youth. For a time he worked in a western show owned by early cowboy actor Tom Mix. In 1940 he traveled to South America, where he competed in rodeos for two years. After his return to the U.S., he played small parts in the 1943 film Stage Door Canteen, and the 1944 film Janie, both having him billed as “Michael Harrison”. Catching the attention of Republic Pictures executive Lou Grey, he was signed to a contract and given his own series of B-westerns, along with having his name changed to “Sunset Carson”. Within two years, Carson was on the top-10 list of money makers for western stars. He was given a horse named “Cactus”, and starred in a string of semi-successful western genre films. In 1944 he starred in Bordertown Trail, Code of the Prairie, and Firebrands of Arizona opposite Smiley Burnette. 1945 was by far the peak of his career, with his first film of that year being Sheriff of Cimarron. He followed that up with Sante Fe Saddlemates, Bells of Rosarita, Oregon Trail, Bandits of the Badlands, Rough Riders of Cheyenne and The Cherokee Flash. In 1946, Carson began the year strong, starring in Days of Buffalo Bill and Alias Billy the Kid. He followed those with The El Paso Kid, Red River Renegades, and Rio Grande Raiders. However, by the end of 1946, Carson and Republic Pictures were having disputes. He claimed the disputes were over his contract. Republic Pictures would later claim that he was fired by Republic creator and executive officer Herbert Yates after attending a studio function while intoxicated and in the company of an underage girl. At any rate, by the years end he and Republic Pictures had parted company. He would never again achieve any large success as an actor.

In 1948 he starred with another company in Fighting Mustang, Deadline, and Sunset Carson Rides Again. Then in 1949 he starred in Rio Grande, and in 1950 he starred as the main character for the last time, in Battling Marshal. By the following year, his career was all but over as a leading actor of the day. For the next several years he obtained small bit parts. He played the lead role in a B-movie titled The Marshal of Windy Hollow in 1972, a film that costarred a host of old time actors, including Ken Maynard, Tex Ritter, and Bill Cody, Jr.. He then had a bit part in the movie Seabo in 1978, and another bit part in the 1985 sci-fi Alien Outlaw. He toured for five years with “Tommy Scott’s Country Music Circus”. In the early 1980s, Carson hosted ″Six-Gun Heroes″, a South Carolina Educational TV (SCETV) show presenting classic B Westerns which still airs on many PBS affiliates across the US. His last known role was in the first episode of the television series Simon & Simon, in 1985. He married five times in his lifetime. He married Patricia Hussey in 1938, which ended in divorce. He then married Betty Price, Dorothy Shockley, and Margaret Nesbitt, all ending in divorce. His last marriage was to Jean Davis in 1989. He retired to Reno, Nevada. He died there on May 1, 1990.