Clark died following a massive heart attack. He had entered St. John's Hospital in Santa Monica on Tuesday night for an outpatient procedure.
Clark first stepped on stage as host of "American Bandstand" in the late 1950s in his trademark suit and tie. He introduced rock 'n' roll into millions of homes and helped to make it respectable. He gave artists like Chubby Checker their first big break and opened the show to black artists.
"He reshaped the television landscape forever as a creative and innovative producer," said President Barack Obama in a statement. "But more important than his groundbreaking achievements was the way he made us feel - as young and vibrant and optimistic as he was."
An appearance on "American Bandstand" launched many a musical career, and from Jerry Lee Lewis to Janet Jackson, they all wanted Clark to give their record a spin.
"I knew when I was 13 what I wanted to do. It's very rare. I walked into a radio studio and saw Jimmy Durante and Garry Moore do a radio show, and I said, 'Wow, what a great way to make a living,'" Clark said in the past.
Clark used his fame to build an entertainment empire, producing the American Music Awards, hosting game shows and most famously helping the country count down the New Year. Clark was at his post in Times Square for more than 30 years - even a stroke only briefly stopped the celebration.
For a time in the 1980s, he had shows on all three networks and was listed among the Forbes 400 of wealthiest Americans.
"It can be embarrassing. People come up to me and say, 'I love your show,' and I have no idea which one they're talking about," Clark told The Associated Press in 1985.
He was inducted into the Rock and Roll Hall of Fame in 1993 and received the lifetime achievement award from the television academy in 2010.
Fans and celebrities around the world are remembering Clark. Ryan Seacrest, who took over main hosting duties on the countdown show from Clark after years of working beside the legend, described him as "smart, charming, funny and always a true gentleman."
"I idolized him from the start, and I was graced early on in my career with his generous advice and counsel," Seacrest said in a statement. "I learned a great deal from him, and I'll always be indebted to him for his faith and support of me."
He is survived by his wife Kari and his three children, RAC, Duane and Cindy. Flowers covered his Hollywood Walk of Fame Star at the corner of Sunset Boulevard and Vine Street.
The Associated Press contributed to this report.