One of five children of a single mother, he grew up in several troubled neighborhoods, including time in a homeless shelter when he was in middle school before the family moved to Antioch.

[8] Harris received offers from multiple top football programs including the Alabama Crimson Tide, Michigan Wolverines, Ohio State Buckeyes, USC Trojans, and Notre Dame Fighting Irish.

[17] Harris had his best game against Arkansas State, carrying the ball 13 times and gaining a career-high 135 yards.

[28] Despite speculation that he would declare for the 2020 NFL draft, Harris announced that he would return to Alabama for his senior year.

[40][41] In the Semifinals, the Rose Bowl against Notre Dame, Harris had 15 carries for 125 rushing yards in the 31–14 victory.

[51] In Week 3 against the Cincinnati Bengals, Harris recorded 142 all purpose yards, including 14 catches in 19 targets.

[52] In Week 5 against the Denver Broncos, Harris recorded 122 yards on 23 carries and a rushing touchdown in the 27–19 win.

[54] In Week 17, Harris ran for a career-high 188 yards and the game-sealing touchdown in a 26–14 win over the Cleveland Browns.

[58] He was selected as an alternate for the 2022 Pro Bowl, replacing Bengals running back Joe Mixon.

It brought into question whether the Lisfranc sprain he suffered in training camp was affecting his production, although Harris claimed that was not the case.

Harris rushed for a season high 111 yards and caught the game winning touchdown from rookie quarterback Kenny Pickett with less than a minute to play.

Harris seemed to be pessimistic about the season's outlook, stating to reporters in a post-game locker room interview that the poor play was "fixable" but questioned whether or not it would be fixed.

[74] Harris would then make his second post-season appearance of his career in the AFC Wild Card Round against the Buffalo Bills on January 15, 2024.

[75] On May 2, 2024, the Steelers declined the fifth-year option on Harris' contract, making him a free agent after the 2024 season.

[78] In the Week 6 win over the Las Vegas Raiders, Harris would score his first touchdown of the season on a 36 yard rush.

[79] Harris would hit the century mark again in the following week against the New York Jets, rushing 21 times for 102 yards and, with less than 30 seconds left in the game, another touchdown to seal the win.

[81] Harris made another postseason start with the Steelers in their 28–14 loss to the Baltimore Ravens during the AFC Wild Card round in which he had six carries for 17 yards.

[83] During his last college football season, Harris began celebrating touchdowns by striking the iconic World Cup pose of Megan Rapinoe.

[85] On the day of the 2021 NFL draft, Harris declined the invitation to the event in Cleveland, Ohio, opting instead to host a party for the kids served at Greater Richmond Interfaith Program, the homeless shelter he spent his childhood at.

He later gathered with family and friends to watch the draft at a restaurant owned by Marshawn Lynch, in Emeryville, California.