High school career
Born in East York, Ontario, Jackson attended Findlay Prep in Henderson, Nevada. In his junior year, he along with Allonzo Trier, played in the 2015 Dick's Sporting Goods High School National s at Christ the King Regional High School in Middle Village, Queens, New York. Findlay Prep entered the tournament as the #8 ranked team. On April 3, 2015, Findlay Prep loss to Ben Simmons and #2 ranked Montverde Academy (57-53) in overtime in the semi-finals of the Tournament. On the season Jackson averaged 14.1 points, 7.1 rebounds per game, and 2.2 steals per game, while leading the Pilots to a (29-2) overall record. During the spring and summer of 2015, Jackson competed on the Under Armour Association Circuit for the AAU team, Canada Elite. Jackson and Current NBA player Thon Maker led Canada Elite to the Under Armour Association 17u championship game in Suwanee, Georgia. Canada Elite would lose to Team Charlotte (56-46) in the Championship game. Jackson participated in the NBPA Top 100 camp on June 22, 2015 at John Paul Jones Arena in Virginia. After his junior season concluded, Jackson transferred to Hill Academy in Vaughan, Ontario. As a senior, he was named a First Team all-star of the Ontario Scholastic Basketball Association in 2016.
Jackson was rated a Four-star recruit and ranked consensus top-40 recruit in the Class of 2016 according to ESPN. On May 27, 2016, Jackson committed to the University of Maryland. In his freshman season at Maryland he averaged, 10.5 points and 6.0 rebounds per game. After the season he declared for the 2017 NBA Draft but later withdrew his name from the draft.
On May 24, 2017, Jackson announced he will return to Maryland for his Sophomore season. On December 28, 2017, it was announced that Jackson suffered a torn labrum in his right shoulder. He missed the remainder of the season.  In just 11 games, Jackson averaged 9.8 points, 8.1 rebounds, and 1.9 assists.