Ajay Mitchell began playing for Limburg United's youth team in 2019 and made two appearances with the senior team in the Pro Basketball League during the 2019-2020 season. Mitchell played solely with the senior team during the 2020-2021 season while maintaining his amateur status. After the season, Mitchell decided to play basketball in the U.S. and committed to UC Santa Barbara.
Mitchell played in 27 games during his freshman season and was named the Big West Conference Freshman of the Year and second team All-Big West after averaging 11.6 points, 3.7 assists, and 2.2 rebounds per game. As a sophomore, Mitchell took his game to the next level. He was named the Big West Player of the Year. He averaged 16.3 points, 5.1 assists, and 2.7 rebounds per contest.
This past season, Mitchell continued his growth as a complete player. He was named first team All-Big West after averaging a career high in points with 20.0 per game. After the season, Mitchell announced that he was entering the NBA Draft.