Walker played college football at Southern Methodist University (SMU) in Dallas, where he was a running back, defensive back, and place kicker. He also threw and caught passes, punted, and returned kicks. He was a three-time All-American, in 1947, 1948, and 1949. He won the Maxwell Award as a sophomore in 1947 and the Heisman Trophy in 1948 as a junior. Walker's impact on SMU and football in the Dallas area led to the Cotton Bowl being referred to as "The House That Doak Built." Walker was also a member of Phi Delta Theta Fraternity, the men's honorary Cycen Fjodr and lettered on the SMU basketball and baseball teams. In 2007, he was ranked #4 on ESPN's list of the top 25 players in college football history.
Walker was selected third overall in the 1949 NFL draft in December 1948 by the Boston Yanks. The Detroit Lions acquired his draft rights in January 1950, where he was once again played with former high school teammate Layne. Although Walker was only 5 ft 11 in (1.80 m) and 175 lb (79 kg), he was voted All-Pro four times, and he helped lead the Lions to consecutive NFL championships in 1952 and 1953. Walker also led the NFL in scoring twice (1950 and 1955) and tallied 534 points in his career (330 on field goals and extra points). In honor of his achievements, the Lions retired his number 37. He is a member of the Pro Football Hall of Fame, inducted in 1986.
Walker married his high school sweetheart, and they had four children. He later married Olympic skier Skeeter Werner. Doak Walker died in September 1998 as a result of paralyzing injuries suffered in a skiing accident eight months earlier. His death came 50 years to the day that he was featured on the cover of LIFE magazine in 1948. He is immortalized by the annual Doak Walker Award, given to the best running back in college football, and by a statue placed between Gerald Ford Stadium and SMU's state-of-the-art Dedman Center for Lifetime Sports.
"He's Doak Walker, and he was as golden as golden gets. He had perfectly even, white teeth and a jaw as square as a deck of cards and a mop of brown hair that made girls bite their necklaces. He was so shifty you couldn't have tackled him in a phone booth, yet so humble that he wrote the Associated Press a thank-you note for naming him an All-American. Come to think of it, he was a three-time All-American, twice one of the Outstanding Players in the Cotton Bowl, a four-time All-Pro. He appeared on 47 covers, including Life, Look and Collier's. One time, Kyle Rote, another gridiron golden boy, saw a guy buying a football magazine at a newsstand. 'Don't buy that one,' Rote said. 'It's not official. It doesn't have a picture of Doak Walker on the cover.'" 
However, fellow Sports Illustrated writer Paul Zimmerman cited Walker as the least deserving member of the Pro Football Hall of Fame.
Shortly after Walker's death in 1998, Texasrunning backRicky Williams wore Walker's number 37 in a game as opposed to his customary number 34 in remembrance of Walker. Williams would go on to set the NCAA all-time rushing record that season (though it has since been eclipsed by Ron Dayne), winning the Heisman Trophy in the process.