Dean Smith was raised in Eliasville, Texas, and later lived in Breckenridge, Texas, where he raised horses and longhorn cattle. He attended the University of Texas at Austin where he competed in track and football. He won an Olympic gold medal for the 400-meter relay in the 1952 Helsinki games and finished fourth in the 100 dash in the closest race in Olympic history. He was the lead-off man on the University of Texas world record relay team, 1954-55, and AAU national champion in the 100-meter dash. He played with the Los Angeles Rams during exhibition season and was traded to the Pittsburg Steelers at which time he decided to enter the movie business. He also won amateur rodeo championships for bareback bronco riding and calf roping.

He was an honorary member of the Professional Rodeo Cowboys Association, was inducted into the Texas Rodeo Cowboy Hall of Fame (2006), the Texas Sports Hall of Fame (1985), Stuntman's Hall of Fame (1980), and the University of Texas Hall of Fame (1980). He was awarded the American Culture Award for Western Movies and Television (2000), the Golden Boot Award in 1998, the Ben Johnson Award in 1993, the All-American Cowboy Award in 1997, and the Head of the Class Alvin Davis Award in 2002.

In 2002, he organized the Dean Smith Celebrity Rodeo benefiting the Cowboy Cancer Crusade tribute to Ben Johnson, the Dean Smith Celebrity Rodeo benefiting the John Wayne Cancer Institute honoring John Wayne, and, in 2006, the Dean Smith Celebrity Rodeo benefiting the John Wayne Cancer Institute honoring The Singing Cowboys in Abilene, Texas, the third weekend in October. On April 8, 2006, the John Wayne Cancer Institute honored him with the "Duke Award" for his contributions to cancer research.

In 2023, Dean Smith died of cancer, aged 91, in Breckenridge, Texas.