[2] Lawson committed to playing college basketball for South Carolina over offers from Tulane and Creighton.

South Carolina head coach Frank Martin began recruiting Lawson after a late night workout in Columbia on the trip back from a tournament.

[4][5] He was named the SEC Freshman of the Week on November 19, 2018, after averaging 15.7 points, 6.3 rebounds and 5.3 assists over a three-game stretch against Norfolk State, Providence and George Washington.

[7][8] Lawson was named to the preseason first team All-SEC and to the Jerry West Award watchlist going into his sophomore year.

[9][10] He was also named the 41st-best collegiate basketball player going into the 2019–20 season by CBS Sports and the 29th-best prospect for the 2020 NBA draft by ESPN.

[31] On December 26, 2022, Lawson signed a two-way contract with the Dallas Mavericks, splitting time with their NBA G League affiliate, the Texas Legends.

He averaged 14.8 points, 5.4 rebounds and 1.2 assists per game in the 2018 FIBA Under-18 Americas Championship as Canada finished second in the tournament.

[43] Lawson posted team highs with 18 points and 12 rebounds in Canada's 113–74 loss to the United States in the tournament final.

[46] Lawson made his debut with Canada's senior men's national team during the first round of the FIBA Basketball World Cup 2023 Americas Qualifiers.