She soon became the most popular Mouseketeer, receiving 8,000 fan letters a month, 10 times more than any of the 23 other young performers.
Her devotion to Walt Disney remained throughout her life.
"He was the dearest, kindest person and truly was like a second father to me," she said. "He was a kid at heart."
When "The Mickey Mouse Club" ended, Annette (as she was often billed) was the only club member to remain under contract to the studio. She appeared in such Disney movies as "Johnny Tremain," ''The Shaggy Dog," ''The Horsemasters," ''Babes in Toyland," ''The Misadventures of Merlin Jones" and "The Monkey's Uncle."
She also became a recording star, singing on 15 albums and hit singles such as "Tall Paul" and "Pineapple Princess."
Outgrowing the kid roles by the early '60s, Annette teamed with Avalon in a series of movies for American-International, the first film company to exploit the burgeoning teen market.
The filmmakers weren't aiming for art, and they didn't achieve it. As Halliwell's Film Guide says of "Beach Party": "Quite tolerable in itself, it started an excruciating trend."
The films had songs, cameos by older stars and a few laughs. The 1965 "Beach Blanket Bingo," for example, featured subplots involving a mermaid, a motorcycle gang and a skydiving school run by Don Rickles, and comic touches by silent film star Buster Keaton.
Among the other titles: "Muscle Beach Party," ''Bikini Beach," ''How to Stuff a Wild Bikini" and "Dr. Goldfoot and the Bikini Machine."
The beach films also featured ample youthful skin. But not Funicello's.
She remembered in 1987: "Mr. Disney said to me one day, 'Annette, I have a favor to ask of you. I know all the girls are wearing bikinis, but you have an image to uphold. I would appreciate it if you would wear a one-piece suit.' I did, and I never regretted it."