She died peacefully at Mercy Southwest Hospital in Bakersfield, Calif., of complications from multiple sclerosis, Walt Disney Co. said Monday.
"She will forever hold a place in our hearts as one of Walt Disney's brightest stars, delighting an entire generation of baby boomers with her jubilant personality and endless talent," Disney CEO Bob Iger said in a statement.
Though she was born in New York, Funicello's family moved to Los Angeles when she was just four. In the mid-1950s, the pretty, dark-haired youngster gained widespread fame when, at the young age of 13, she became an original member of what would become Disney's The Mickey Mouse Club.
She appeared in a host of Disney films, including Johnny Tremain, The Shaggy Dog and Babes in Toyland, and recorded hit songs such as Tall Paul and Pineapple Princess.
She transitioned into a teenage star opposite pop singer Frankie Avalon in the popular Beach Party films of the mid-1960s, including the classic Beach Blanket Bingo.
Funicello never realized how beloved she was, Avalon said on Monday.
"She would say, 'Really?"' he told The Associated Press. "She was so bashful about it. She was an amazing girl."
He added: "She really had a tough existence. It's like losing a family member. I'm devastated, but I'm not surprised."
Revealed illness in 1992
Funicello revealed in 1992 she was grappling with MS. She spoke openly about its degenerative effects on her, wrote about the illness in her memoir A Dream Is a Wish Your Heart Makes, published two years later, and also appeared in a television docudrama based on her book.
"My equilibrium is no more; it's just progressively getting worse," she said. "But I thank God I just didn't wake up one morning and not be able to walk. You learn to live with it. You learn to live with anything, you really do."
However, in recent years she had withdrawn from the public eye.
She is survived by her second husband, Glen Holt, and her children Gina, Jack and Jason with first husband Jack Gilardi.