Bobby Humphrey played from 1985 to 1988 for the Crimson Tide. During his freshman year, he would share the backfield with Gene Jelks and Kerry Goode. He would rush for 502 yards, on 99 carries, and 4 touchdowns. During his sophomore year, he led the Crimson Tide in rushing with 1,471 yards and scored 15 touchdowns. The season ended on Christmas Day in the Sun Bowl against the Washington Huskies. Humphrey scored three touchdowns, and the Tide finished with a 10-3 record. He was named to an All-American team.
In 1987, Bobby Humphrey was once again the featured back for the Tide. Rushing for 1,255 yards on 238 carries, and 11 touchdowns. One of the highlights of his junior year, was a 220-yard rushing performance against Penn State. On Halloween night, against Mississippi State he would pass Johnny Musso as Alabama's all-time leading rusher. Alabama would finish the year in the 1988 Hall of Fame Bowl, where Humphrey would score two touchdowns in a losing effort. He was once again named to an All-American team, and finished tenth in the Heisman Trophy voting.
During spring practice, he would break his left foot. He started his senior season against Temple, scoring a touchdown. But two weeks later, he would break his foot again ending his college career. He finished with 3,420 rushing yards and 33 touchdowns. At the end of his college career, no Alabama running back had more 200 yard rushing games, with four, and more 100 yard rushing games, with sixteen, than Bobby Humphrey.
Humphrey was one of five players selected in the 1989 NFL Supplemental Draft, selected in the first round by the Denver Broncos.
During his rookie season, he rushed for 1,151 yards and seven touchdowns for the Broncos as they qualified for Super Bowl XXIV, but were defeated 55-10 by the San Francisco 49ers. Humphrey, although finishing the game as the Broncos leader in both rushing (61 yards) and receiving (31 yards), had a key turnover in the first quarter when he fumbled near midfield. Following this fumble, the 49ers would score 34 unanswered points to put the game away. Humphrey was not named NFL Rookie of the Year, due to Barry Sanders' incredible 1,470-yard rookie campaign. He followed his impressive rookie performance with a Pro Bowl selection in 1990, rushing for 1,202 yards and seven touchdowns in 1990. Humphrey was the first Denver Bronco to rush for 1,000 yards in back-to-back seasons.
In 1991, Humphrey held out of training camp in hopes of obtaining a new contract. The Broncos, by team policy, refused to renegotiate his pay and the holdout continued late into the season.
Unable to secure a new contract, Humphrey finally ended his holdout in week 14. However, by that time, newly signed Gaston Green had emerged as the team's starting running back and was on his way to completing his own 1,000-yard season. Furthermore, Humphrey had fallen out of favor with the team's coaching and front office as a result of the holdout. When Humphrey returned in week 14, he was out of shape and given only a reserve role in the Broncos' offense. He remained on the bench as Denver made a run to the AFC Championship Game, losing to the Buffalo Bills 10-7.
The following offseason he was traded to the Miami Dolphins in exchange for running back Sammie Smith. He played for the Dolphins in 1992 scoring only one touchdown and running for 471 yards. With his new team, Humphrey returned to the AFC Championship Game for the second consecutive season, losing again to the Buffalo Bills. After being out of football for two seasons, Humphrey attempted a comeback in 1995 with the Bills, but failed to make the team.
In August 1999, the Birmingham Steeldogs formed as part of a new indoor football league called AF2, a developmental league for the Arena Football League. Humphrey, with no coaching experience at that level, was named Head Coach. Over the course of six season, Humphrey guided the Steeldogs to a 51-50 record. After a disappointing 2-14 season, Humphrey was dismissed in 2005. The Steeldogs would rename themselves as the Alabama Steeldogs one year later, before ceasing operations following the 2007 season. The league would fold in 2009. Humphrey, at the time of his dismissal, was the second winningest coach in the league.
Bobby Humphrey is married. He and his wife Barbara have five children. Two of his sons have gone on to play college football. Maudrecus Humphrey played for the University of Arkansas. Marlon Humphrey followed his father's footsteps and played for Alabama, donning his father's jersey number 26, before being selected 16th overall by the Baltimore Ravens in the 2017 NFL Draft. In 1998, he returned to the University of Alabama, and earned a bachelor's degree in Social Work. In 2004, he was inducted into the Alabama Sports Hall of Fame.
During his time coaching in AF2, he owned and operated Humphrey Construction Company. As of 2012, Humphrey is vice president of business development for Bryant Bank in Birmingham, Alabama.
He was appointed to the City of Hoover's Parks and Recreation Board in 2014.
In the summer of 2016, Humphrey was one of 75 players to be eligible for the 2017 Class for the College Football Hall of Fame.