Texas Tech 2019–20 season Shannon entered his
freshman season as one of Texas Tech's starting
guards. On December 4, 2019, Shannon recorded a freshman season-high 24 points and eight rebounds in a 65–60 overtime loss to DePaul. As a freshman, he averaged 9.8 points and 4.1
rebounds per game, earning
Big 12 Conference All-Freshman Team honors.
2020–21 season Entering his
sophomore season, Shannon was named to the
Julius Erving Award watch list. On January 30, 2021, Shannon registered his first career
double-double with 23 points and 10 rebounds against
LSU. Going into the
Big 12 tournament, the Red Raiders were 9–8 in the Big 12, good enough to earn the 6-seed. During their quarterfinal matchup against
Texas, Shannon played 34 minutes making four
three-point field goals in way of an 18-point outing. Despite his performance, Texas Tech was eliminated by a score of 67–66. The Red Raiders were then granted the 6-seed in the South Region of the
NCAA tournament. In their Round of 32 matchup against
Arkansas, Shannon scored 20 points despite the Red Raiders being eliminated. As a sophomore, Shannon averaged 12.9 points, four rebounds, 1.4
assists, and 1.1
steals per game. For his efforts, he earned Third-team All-Big 12 honors. On April 8, 2021, Shannon declared for the
2021 NBA draft while maintaining his college eligibility. He ultimately returned to Texas Tech for a third season.
2021–22 season On November 7, Shannon was suspended indefinitely due to an eligibility review. He was reinstated on November 17, after missing three games. As a junior, he averaged 10.4 points, 2.6 rebounds, and two assists per game. On March 25, 2022, Shannon entered the
NCAA transfer portal.
Illinois 2022–23 season On April 29, 2022, he committed to
Illinois. After his first season at Illinois, he declared for the
2023 NBA draft and played in the NBA draft combine. He later withdrew from the draft and returned to Illinois for a second and final season.
2023–24 season Shannon played 11 games for the Illini before being suspended for six games, Shannon was considered a front-runner for the
National Player of the Year award before his suspension. After a preliminary injunction was granted, his suspension was ended and he resumed playing the rest of the season. Following the season's end and the not-guilty verdict, it was announced that Shannon's jersey would be
honored by the university. His number 0 jersey was unveiled in a halftime ceremony on February 15, 2025, with Shannon in attendance; due to an error by the athletic department, the jersey was initially hung upside down. Making light of the situation, Shannon partnered with Gameday Spirit to release t-shirts referencing the mishap, with a portion of the proceeds going to the local Don Moyer Boys & Girls Club of Champaign.
Records Big Ten Conference • Big Ten men's basketball tournament single-game record for most points scored: 40 (March 16, 2024)
Illinois Fighting Illini •
Fighting Illini single-season record for most points scored: 736 (2023–24) •
Fighting Illini single-season record for most free throws made: 212 (2023–24) •
Fighting Illini single-season record for most free throws attempted: 260 (2023–24) • Fighting Illini single-season record for most offensive win shares: 4.9 (2023–24) • Fighting Illini single-season record for highest box plus-minus score: 11.6 (2023–24) • Fighting Illini single-season record for highest offensive box plus-minus score: 9.1 (2023–24) • Fighting Illini single-game record for most three-point field goals made: 8 (November 18, 2022) • Tied with
Dee Brown (2005),
Trenton Meacham (2006),
Brandon Paul (2012), and
Alfonso Plummer (2022) ==Professional career==