Williams was heavily recruited by then Kansas head coach David Beaty, and signed with Kansas in 2018. Williams played his first game at Kansas in their second game of the season against Central Michigan. He ran for 125 yards and 2 touchdowns as he helped lead Kansas to their first road victory since 2009. The following week, he rushed 161 yards and 1 touchdown. He would go on to rush for over 100 yards two more times during the season, including recording 252 rushing yards against Oklahoma. Williams finished the season with 1,125 yards and 7 touchdowns. For his performance as a freshman, Williams was named 1st Team All-Big 12 and Offensive Freshman of the Year.
