RaJae' Johnson's collegiate career started in 2018 at San Mateo Junior College. After an impressive stat line of 56-1385-14 at San Mateo, he ranked as the top JUCO WR and chose UAB as his next destination. He redshirted his first season at UAB in 2019. Johnson barely played in 2020, finishing with two receptions in eight games.
2021 saw Johnson finish third on the team in receiving yards (394), more than 300 yards less than the No. 2 wide receiver, Gerrit Prince. With one final season of eligility left, Johnson opted to transfer to Troy for the 2022 season. In his lone season, Johnsno finished with 36 receptions for 713 receiving yards (19.8 yards per reception), and a team-high seven receiving touchdowns.