As a true freshman at Maryland in 2021, Jackson Jr. played in all 13 games with one start and had 22 tackles. After one year at Maryland, he transferred to the University of Miami. In his lone year at Miami, he started all 12 games and had 27 tackles and three sacks. After the season, Jackson Jr. transferred to Florida State University. He was forced to sit out the season by the NCAA after he was denied a hardship waiver request, but was eligible to play in a bowl game. His only game of the season came in the 2023 Orange Bowl, where he recordedsix tackles. Jackson Jr. returned to Florida State in 2024.