The Emmy-award winning star died at his Los Angeles home on Tuesday, his widow Donna Brown Guillaume said.
Samuel L Jackson, Billy Crystal and Nancy Sinatra are among those paying tributes with the former saying Guillaume was “Class, Grace & Talent Personified” in a post on Twitter.
Crystal tweeted: “Sad to hear of the passing of Robert Guillaume. He was a great support to me on Soap. Great timing, charisma and class. Rest in Peace.”
Sinatra wrote: “Godspeed, sir, and condolences to friends and family.”
Actor Jesse Williams posted: “RIP to EmmyAward winning Army vet, star of stage & screen, Robert Guillaume. 1st black actor to play the title role in Phantom of the Opera.”
Selma director Ava DuVernay shared several photos of Guillaume on Instagram and praised him for being one of the first celebrities to appear at AIDS fundraisers.
George Takei wrote: “Another light has left us. Robert Guillaume, you were beloved across America and brought laughter always with you.”
Josh Charles - who co-starred alongside Guillaume in Sports Night - shared a personal account of the actor.
He wrote: “Robert Guillaume radiated such warmth, light, dignity, and above all, class. That smile and laugh touched us all. RIP to the best boss ever. Making him laugh gave me such pleasure. Remembering those moments now, I’m tearing up. I loved that man. My thoughts are with his family.”
Guillaume voiced Rafiki in the Lion King and was the first black actor to the title role in Phantom Of The Opera.