He played college football for the Notre Dame Fighting Irish and was selected by the Rams in the fifth round of the 2022 NFL draft.

[17] After not playing in the preseason, on September 8, 2022, Williams suffered a high ankle sprain on the first kick return in the Rams' season-opening 31–10 loss to the Buffalo Bills.

[22] In the season opener against the Seattle Seahawks, Williams carried 15 times for 52 yards and scored his first two career touchdowns in a 30–13 win on the road.

[24] On the road at Indianapolis in Week 4, Williams recorded his first career 100-yard rushing game, totaling 103 yards on 25 carries with two touchdowns in the Rams' 29–23 overtime victory against the Colts.

[25] During Week 6 against the Arizona Cardinals, Williams finished with a season-high 158 rushing yards and a touchdown on 20 carries as the Rams won 26–9 but sprained his left ankle in the process.

[32] Four days later, Williams turned in his third straight 100-yard rushing game, totaling 104 yards (including a 10-yard TD) on 22 carries as the Rams defeated the visiting New Orleans Saints 30–22.

[34] In Week 17 at the New York Giants, Williams had 87 yards on 20 carries but scored a career-high three touchdowns in the Rams' playoff-clinching 26–25 victory.

[40] Beginning the season as the starting running back, Williams scored one touchdown in each of the Rams' first two games, both losses on the road.

Following a bye week, Williams ran 21 times for 76 yards and two scores in the Rams' 20–15 victory over the Las Vegas Raiders.

[42] In Week 17, Williams totaled 56 yards on 13 carries with a touchdown run in L.A.'s 13–9 win over Arizona that led to the Rams clinching the NFC West title.

A week later in an NFC Divisional Playoff against Philadelphia, Williams ran for 106 yards on 19 carries but lost a critical fumble in the fourth quarter of the Rams' 28–22 loss.