Robert Guillaume ( born Robert Peter Williams ; November 30 , 1927 ) is an American stage and television actor , known for his role as Benson on the TV-series `` Soap '' and the spin-off `` Benson '' , voicing the mandrill Rafiki in `` The Lion King '' and as Isaac Jaffe on `` Sports Night '' .
Robert Guillaume ( born Robert Peter Williams ; November 30 , 1927 ) is an American actor . He is known for his role as Benson on the TV-series `` Soap '' and the spin-off `` Benson '' , voicing the mandrill Rafiki in `` The Lion King '' and as Isaac Jaffe on `` Sports Night '' .