As a black actor, Guillaume broke ground in the theater scene, performing in the first all-black version of Guys and Dolls His role as Nathan Detroit in the musical earned him a Tony Award nomination in 1977. In addition to many stage roles, Guillaume was the first black actor to play the title role in Phantom of the Opera during the Los Angeles production. 

His television career spanned many decades, but it was his role on ABC’s Soap (1977-1979) and the spin-off series Benson (1979-1986) that earned him recognition. He won an Emmy for both shows playing the acerbic, dry-witted butler Benson Du Bois. He also starred in the short-lived critically acclaimed Aaron Sorkin series Sports Night (1998-2000 where he played television executive Isaac Jaffe.

His TV career was diverse and plentiful throughout the decades with roles in Good Times, The Jeffersons, Sanford and Son, Pacific Station, The Fresh Prince of Bel-Air, A Different World, All in the Family as well as The Robert Guillaume Show. He also appeared in the television mini-series North and South as abolitionist Fredrick Douglass.

In film, he is known as the voice of Rafiki in Disney’s classic animated feature The Lion King. He went on to reprise his role as the mandrill shaman in spin-offs and sequels of the movie. His film credits also include Lean on Me, The Meteor Man, First Kid, Spy Hard, and Big Fish.