Friends and colleagues of Boseman posted messages on social networks to say goodbye to the U.S. star.
"All I have to say is that the tragedies, which have accumulated this year, were made more profound by the loss of Chadwick Boseman. What a man and what an immense talent! Brother, you were one of the greatest of all times," actor Mark Ruffalo lamented.
"I am devastated. This is more than heartbreaking. Chadwick was special. He was a deeply committed artist with an incredible amount of work left to create. I am infinitely grateful for our friendship. Rest in Power, King," actor Chris Evans tweeted.