In his junior season, he averaged 10.5 points, 7.2 rebounds, 2.8 assists, and 2.1 blocks per game and lifted the Clippers to a win over Norristown High School to claim the PIAA Class AAAA state title.

[1] After leaving Temple, Hollis-Jefferson signed his first professional contract with AB Contern of the Total League in Luxembourg.

[3] On October 13, 2015, Hollis-Jefferson signed with the Saint John Mill Rats of the National Basketball League of Canada (NBL).

[8] On December 14, 2023, he signed with the TNT Tropang Giga of the Philippine Basketball Association (PBA) to replace Quincy Miller as one of the team's import for its participation in the 2023–24 East Asia Super League.

However, Rahlir replaced his brother Rondae as the team's import for the 2023–24 PBA Commissioner's Cup due to the latter's injury.

[11] On May 4, Hollis-Jefferson had suffered the Achilles tendon rupture during the semifinals series game 1, and he would miss the remainder of the 2023–24 season.

[12] On December 23, Hollis-Jefferson returned to the Taipei Taishin Mars of the Taiwan Professional Basketball League (TPBL).