- Mr Gregory performed in the country's top clubs in the early 1960s
- Dick Gregory was credited with laying the groundwork for black comics
- 'Condolences to his family,' tweeted Whoopi Goldberg
In a Facebook post, Christian Gregory did not give the cause of death but said his father started feeling ill on August 9, and was admitted to a hospital on August 12. He died in Washington.
"A life well-lived but heavily sacrificed, has definitively taken its toll," the son said. More details were to be released in the coming days.
Mr Gregory performed in the country's top clubs in the early 1960s and was not shy about confronting his white audiences with the realities of racism.
"A Southern liberal?" he once said, according to the Washington Post. "That's a guy that'll lynch you from a low tree."
Or his line about trying to order at a restaurant in the segregated South and being told by the waitress, "We don't serve coloured people here."
Mr Gregory replied, according to the New York Times, "That's all right, I don't eat coloured people. Just bring me a whole fried chicken."
Mr Gregory was credited with laying the groundwork for black comics who would come later, particularly Bill Cosby and Richard Pryor.
Later on in the 1960s, he became a fervent front-line activist on various racial and social causes. He staged a modest write-in campaign for president in 1968 that garnered fewer than 50,000 votes.
In later decades, he became known variously as a prodigious hunger striker, conspiracy theorist, diet guru and health food advocate.
"He taught us how to laugh. He taught us how to fight. He taught us how to live. Dick Gregory was committed to justice. I miss him already. #RIP," civil rights activist the Reverend Jesse Jackson said.
"Dick Gregory, Truth teller, make you fall on your face laughing Comedian, health man before it was cool & crazy expensive unapologetic About being black in America Dick Gregory has passed away, Condolences to his family and to us who won't have his insight 2 lean on," actress Whoopi Goldberg tweeted.
Dick Gregory, Truth teller, make you fall on your face laughing Comedian, health man before it was cool & crazy expensive unapologetic— Whoopi Goldberg (@WhoopiGoldberg) August 20, 2017
About being black in America Dick Gregory has passed away, Condolences to his family and to us who won't have his insight 2 lean on— Whoopi Goldberg (@WhoopiGoldberg) August 20, 2017
Mr Gregory's death came at a time of anguished national debate over racial relations, a week after a suspected neo-Nazi at a white supremacist rally in Virginia drove his car into a crowd of counter-protesters, killing a woman.
President Donald Trump defended some far-right protesters at the rally as "very fine people."
Mr Gregory, whose Instagram account was checkered with promotions for his many club appearances around the country, touched on the issue in a post from March.
"As I approach my 85th revolution around the sun this year, I wonder why has it been so difficult for humankind to be kind. So difficult to be loving and lovable," Mr Gregory said.
"For my militant brothers and sisters, please don't misconstrue loving and lovable to be weak or submissive. Love will always be triumphant over hate," he added.
"I know I will not be here forever, nor do I desire to be. I have seen progress like most cannot appreciate because they were not there to bear witness. I dedicated my life to the movement. By doing so, I never thought I'd still be here."