Marlon Mack attended Booker High School in Sarasota, FL and proved to be a dual-threat on the football field. In his senior year, Marlon Mack rushed for over 1,500 yards and 19 touchdowns on offense and made 100 tackles with 4 interceptions on defense. Marlon Mack received numerous Division-I scholarship offers but eventually decided to commit to the nearby University of South Florida. In just his first game with the USF Bulls, he tied a school record with 275 rushing yards. He would set the USF freshman record with 1,041 rushing yards and found the end zone nine times.
As a sophomore, Marlon Mack started all 12 games for the USF Bulls and rushed for over 1,300 yards with another nine touchdowns. Marlon Mack surpassed Andre Hall's record to be the all-time leading rusher for USF as a junior, compiling nearly 1,200 rushing yards and 15 touchdowns. After a stellar career in Tampa, Marlon Mack declared for the 2017 NFL Draft.
The Indianapolis Colts selected Marlon Mack in the fourth round of the 2017 NFL Draft. He became the first running back to be drafted from the University of South Florida.
Operating behind future Hall of Famer Frank Gore and Robert Turbin, Marlon Mack was featured in a complementary role for the Indianapolis Colts. However, Mack became the feature back for the Colts in 2018. Mack helped form a dangerous duo with Nyheim Hines and led the Colts to the NFL playoffs. He finished his second NFL season with 908 rushing yards and nine rushing touchdowns.
Marlon Mack has continued to be the Indianapolis Colts feature back and has proven to be a potent offensive weapon for the Colts offense.