The legendary stand-up died of kidney failure at his home in Los Angeles, his publicist confirmed.
Known as the world's greatest insult comic, Rickles enjoyed a career which spanned centuries and found him performing in everything from nightclubs to a Martin Scorsese film.
Rickles and Frank Sinatra were longtime friends and the two goofed on this relationship when Rickles surprised the iconic singer during an appearance on The Tonight Show Starring Johnny Carson.
Rickles made his film debut in 1958 in Run Silent, Run Deep with Clark Gable and Burt Lancaster.
He wouldn't be able to get away with it in quite the same way today, but from the 1950s on, Rickles had a simple, successful recipe.
He was the voice of Mr. Potato Head in the Toy Story franchise and was working on Toy Story 4 at the time of his death.
Don Rickles, the bullet-headed comedian and actor whose pioneering brand of insult comedy earned him the nickname "Mr. Warmth", has died at 90.
Rickles, who had a net worth of $30 million, appeared in many movies but was widely known for guest appearances on TV shows. "No, I don't, but I got it, and it stuck with me and it didn't hurt me", he said.
"Ninety years with Don Rickles weren't enough", Jimmy Kimmel tweeted. Variety series "The Don Rickles Show" lasted a single season in 1969-69, and his mid-'70s sitcom "C.P.O". One of the funniest people that ever lived, you dumb schmuck.
ROBBINS: That's comedian Chris Rock in the 2007 documentary "Mr. Warmth: The Don Rickles Project".
For his standup act, Rickles would begin a show by charging on stage and berating the people sitting down front.
"I just can't tell jokes", he said. "Hit somebody." Sinatra warmed to an unbowed Rickles, the comedian said, because "I didn't show any fear", and he affectionately dubbed him "bullet head" because of his bald pate.
Tom Hanks and Tim Allen are remembering their late co-star Don Rickles tonight.
Rickles set out to be a serious actor, enrolling in New York's American Academy of Dramatic Arts, where one of his classmates was Jason Robards.
Rickles and his wife of 52 years, Barbara Sklar, were close friends and frequent companions of actor/comedian Bob Newhart and his wife, Ginnie.
Los Angeles led to some TV and movie roles, but it was in Las Vegas, the Rat Pack's home base, where Rickles perfected his craft of curmudgeonly humor with sharply timed insults. Funeral services will be private.
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