Stabler became a highly touted football player at Foley High School in Foley, Alabama. He led Foley to a win-loss record of 29–1 over his high school football career—the only loss coming against Vigor High School. He was an all-around athlete in high school, averaging 29 points a game in basketball and excelling enough as a left-handed pitcher in baseball to receive minor-league contract offers from the Houston Astros and New York Yankees. He was an all-American athlete. During his high school career, he earned his nickname "The Snake" from his coach following a long, winding touchdown run.
Stabler was recruited by legendary head coach Bear Bryant at Alabama. Due to NCAA regulations at the time, freshmen were ineligible to play on the varsity in the University Division. Stabler was on the freshman team in 1964, when the Crimson Tide won the National Championship with quarterback Joe Namath.
As a sophomore in 1965, Stabler was used sparingly as a back-up to Steve Sloan at quarterback, following Namath's departure to the AFL. That year, the Crimson Tide won their second consecutive National Championship, finishing the season with a record of 9–1–1. The team defeated the Nebraska Cornhuskers in the Orange Bowl, 39–28.
As a junior in 1966, he took over the quarterback position full-time. He led the team to an undefeated, 11–0 season which ended in a 34–7 rout of Nebraska in the Sugar Bowl. Despite the unblemished record, the Tide was snubbed by the polls, finishing third behind Notre Dame and Michigan State, neither of which played in a bowl.
Expectations were high in Stabler's senior season, though those expectations would not be completely fulfilled. The offense often struggled in 1967, and the defense's performance slipped. During the season, Bryant kicked Stabler off the team for cutting class and partying, though he was given a second chance. The Tide finished with an 8–2–1 record, including a loss to rival Tennessee. Though the season was lackluster, Stabler would provide a memorable moment in the Iron Bowl. Trailing 3–0 in a game drenched by rain, Stabler scampered through the mud for a 47-yard, game-winning touchdown which gave the Tide a 7–3 victory over rival Auburn at Legion Field. The play is commonly referred to as the "Run in the Mud" in Alabama football lore.
Stabler finished his career at Alabama with a 28–3–2 (.879) record as a starter.
Stabler was selected in the second round of the 1968 NFL/AFL Draft by the Oakland Raiders, the reigning AFL champions. He did not get a chance to play until 1970, and during 1968 and 1969 spent time playing with the Spokane Shockers in the Continental Football League. Stabler first attracted attention in the NFL in a 1972 playoff game against the Pittsburgh Steelers. After entering the game in relief of a flu-ridden Daryle Lamonica, he scored the go-ahead touchdown late in the fourth quarter on a 30-yard scramble. The Steelers, however, came back to win on a controversial, deflected pass from Terry Bradshaw to Franco Harris, later known in football lore as the Immaculate Reception.
After suffering severe knee injuries, Stabler became less a scrambling quarterback and more a classic, drop-back passer, known for accurate passes and an uncanny ability to lead late, come-from-behind drives. During the peak of his career, he had a receiving corps consisting of sprinter and 4-time Pro-Bowler Cliff Branch, Hall of Fame receiver Fred Biletnikoff, and Hall of Fame tight end Dave Casper. The Raiders' philosophy was to pound teams with their running game (aided by multiple-time Pro Bowler Marv Hubbard at fullback, and Clarence Davis at tailback), then stretch them with their long passing game. Although Stabler lacked remarkable arm strength, he was a master of the long pass to Branch, and accurate on intermediate routes to Biletnikoff and Casper. As a starter in Oakland, Stabler was named AFC player of the year in 1974 and 1976, and was the NFL's passing champion in 1976. In January 1977 he guided the Raiders to their first Super Bowl victory, a 32–14 win over the Minnesota Vikings. In the 1977 AFC playoffs against the Baltimore Colts, Stabler completed a legendary 4th quarter pass to Casper to set up a game-tying field goal by Errol Mann. This play, dubbed the "Ghost to the Post", sent the game to double overtime, during which the Raiders won 37–31 after Stabler threw a 10-yard touchdown pass to Casper. In the second game of 1978 on September 10, the Holy Roller (Immaculate Deception) Game saw Oakland win 21–20 at San Diego after a 4th quarter forward fumble by Stabler was caught and forward-fumbled by two other players to score a touchdown and win the game, causing the Ken Stabler Rule to be enacted, permitting only the fumbling player to recover the ball in the 4th quarter.
After subpar 1978 and 1979 seasons in which the Raiders failed to make the playoffs, Stabler was traded to the Oilers for Dan Pastorini prior to the 1980 season, after a lengthy contract holdout. Stabler left the Raiders as their all-time leader in completions (1,486), passing yards (19,078), and touchdown passes (150). The Oilers, in turn, saw Stabler as the missing ingredient that could finally get them past the rival Steelers and into the Super Bowl. However Houston lacked the exceptional talent on offense that Stabler had thrived with in Oakland, as Earl Campbell and Casper- who was also acquired in a trade from the Raiders- were the few potent weapons they had. Meanwhile, Pastorini lost the starting job in Oakland to Jim Plunkett after an injury, and Plunkett then led the Raiders over Stabler and the Oilers in the playoffs. Bum Phillips was fired shortly after the season.
Without the popular head coach that rejuvenated an otherwise woeful Houston franchise, Stabler had a mediocre season in 1981 but re-joined Bum Phillips when the New Orleans Saints traded longtime starter Archie Manning to Houston for Stabler and offensive tackle Leon Gray. By this time, however, the 37-year-old Stabler was past his prime and the Saints were still a fairly dismal franchise. The 1983 season was Stabler's best as a Saint. He started 14 games, and while the team's record in those games was only 7–7, Stabler was the starter for the final game of the season, in New Orleans, against the division rival Los Angeles Rams. Had the Saints won that game, they would have finished 9–7 and reached their first trip to the playoffs. But the Rams pulled out the victory late in the 4th quarter, 26–24. The Saints then acquired New York Jets veteran Richard Todd, who like Stabler played for Bryant at Alabama, before the 1984 season and Stabler retired in the middle of that season.
Stabler was the fastest to win 100 games as a starting quarterback, having done so in 150 games, which bettered Johnny Unitas' previous mark of 153 games. Since then, only Terry Bradshaw in 147 games, Joe Montana in 139 games and Tom Brady in 131 games have reached 100 wins more quickly.
In the early part of 1974, Stabler and several NFL stars agreed to join the newly created World Football League. Stabler signed a contract to play for the Birmingham Americans. "I'm as happy as can be. Getting with a super organization and the financial benefits were key factors, but the biggest thing to me is getting back home. Getting to play before the people in the South is where it's at for me. In two years I'll be in Birmingham if I have to hitchhike", he said. "If I can do for the WFL what Joe Namath did for the AFL, I will feel that I have really accomplished something. I was born in the South and raised in the South and played football in the South. Oakland could have offered me as much money as Birmingham but they couldn't have let me play in the South." The WFL would end up folding midway through the 1975 season, and Stabler remained in the NFL without ever playing in the WFL.
For his successes in the NFL, Stabler was named the twenty-seventh greatest quarterback of the post-merger era by Football Nation. The Professional Football Researchers Association named Stabler to the PRFA Hall of Very Good Class of 2014 At the 2016 NFL Honors it was announced that Stabler would be inducted into the Pro Football Hall of Fame. Stabler was officially inducted into the Hall Of Fame on August 6, 2016.
Following his retirement as a player, Stabler worked as a color commentator, first on CBS NFL telecasts, and then on radio with Eli Gold for Alabama football games. Stabler left before Alabama's 2008 season and was replaced by Phil Savage.
Stabler served as chairman of the XOXO Stabler Foundation, a 501(c)3 nonprofit with a mission "to raise funds, build awareness and hope for a variety of charitable causes." Stabler's celebrity golf tournaments in Point Clear, Alabama have raised nearly $600,000 for charitable partner The Ronald McDonald House of Mobile, which serves families of seriously ill and injured children receiving medical treatment at local hospitals.Stabler was featured on a Saturday Night Live skit as the spokesman for a fictional product called the "Lung Brush".
Professional wrestler Jake "The Snake" Roberts adopted his nickname "The Snake" as a tribute to Stabler.
Stabler is featured on the "NFL Legends" team in the video game NFL Street.
Stabler appears in the 2K video game All-Pro Football 2K8
Stabler was married three times: Isabel Clarke from 1968 to 1973, Debbie Fitzsimmons from 1975 to 1978, and Rose Molly Burch from 1984
Stabler had three daughters, Kendra Stabler Moyes (from first marriage), Alexa Rose Stabler, and Marissa Leigh Stabler (from third marriage).
Renowned for being cool and cerebral on the field, Stabler was equally legendary for his off-field exploits, and his partying ways made him a perfect fit for the 1970s Raiders. As he wrote in his autobiography Snake, "The monotony of [training] camp was so oppressive that without the diversions of whiskey and women, those of us who were wired for activity and no more than six hours sleep a night might have gone berserk."
Stabler died of colon cancer on July 8, 2015, at the age of 69. He had been diagnosed with the disease in February 2015. After some initial confusion when The Tuscaloosa News leaked a draft obituary for Stabler before word of his death could be confirmed, his family confirmed his death in a statement issued on July 9.
In February 2016, The New York Times reported that researchers at Boston University discovered high Stage 3 chronic traumatic encephalopathy (CTE) in Stabler's brain after his death. He was buried at Pine Rest Cemetery in Foley, Alabama.