Gillon started his collegiate career at Arkansas-Little Rock, where he averaged 10.6 points in his freshman season. Afterwards, he decided to transfer to Colorado State where, under NCAA transfer rules, he would redshirt during his first year there. During his redshirt sophomore year he would only start one game for Colorado State, and averaged 7.9 points. The following season that number would improve to 13.2 points per game, and he also shot 88% from the free throw line.
After graduating from Colorado State, with one more year of remaining college eligibility Gillon decided to transfer again to Syracuse.[1] His scoring numbers took a dip, averaging 10.5 per game, however he led the team in assists per game with 5.4, which was also his career-best. He also ended up setting the school record for most consecutive free throws made, with 48. That also tied for the third most consecutive free throws made in ACC history. On February 22, 2017, during a game in the Carrier Dome against Duke, Gillon made a last second three pointer to win the game, with a final score of 75–78.
Professional career
2017–18 season
After going undrafted in the 2017 NBA draft, Gillon was taken by the Texas Legends in the annual NBA G-League Draft, where he would play five games and average 3.6 points per game before getting waived on November 28. On December 3, Gillon was picked up by the Erie BayHawks,[2] reuniting with former Syracuse teammate, Andrew White. Gillon had 40 points in a win against the Fort Wayne Mad Ants on March 24, 2018.[3]
John Gillon played for Boeheim's Army in the 2018 edition of The Basketball Tournament. In 4 games, he averaged 14.5 points, 3.5 assists, and 1.8 rebounds per game. Boeheim's Army reached the Northeast Regional Championship before falling to the Golden Eagles.
^"持續打造全聯盟最速隊伍 桃園領航猿網羅速度型後衛吉倫" (Press release). P. LEAGUE+. November 9, 2021. Archived from the original on November 10, 2021. Retrieved November 10, 2021.