Holmes was raised in San Antonio, Texas. After graduating from high school, he played college football for the University of Texas, where he played with future Heisman Trophy winner Ricky Williams. After graduating from the university, he joined the Baltimore Ravens as an undrafted free agent in 1997. In the 1998 season with the Ravens, Holmes rushed over 1000 yards, including one 200-plus yard game, the highest single game total of the season. In addition, he helped the Ravens to win Super Bowl XXXV in 2001.

The following season, Priest Holmes signed with the Kansas City Chiefs. In his first season with the Chiefs, he was the NFL's leading rusher with 1555 yards.

Despite missing the final two games in the 2002 NFL season because of a hip injury, Holmes rushed 1615 yards with 21 touchdowns. In the 2003 season, he broke Marshall Faulk's NFL record for touchdowns in a season with 27. He is one of only two running backs in NFL history to have back to back seasons with 20 or more rushing touchdowns (Shaun Alexander has since accomplished this in 2005), with 21 in 2002 and 27 in 2003. On a pace to repeat the feat in 2004, he suffered an injury that ended his season with 14 touchdowns. His 2005 season was also cut short by injury(a mid-season concussion), and the surprising performance of Larry Johnson in his absence has put his starting role in jeopardy. In fact, it has been reported that new Chiefs coach Herman Edwards has decided to make Johnson starting running back, and if Holmes chooses to return he will most likely serve as Johnson's backup.

Holmes also holds most Chiefs team records in rushing and yards-from scrimmage categories.

Holmes has revealed that he enjoys playing chess in his free time.

Holmes still maintains a home in San Antonio during the NFL offseason.