The cause of death was not disclosed.
Simmons began his career in broadcasting in 1957 with Sports Programs Inc., which became ABC Sports. He was involved in developing "Wide World of Sports" before becoming president of NBC Sports and later ESPN. He was also founding commissioner of the United States Football League, or USFL.
"Chet Simmons' leadership and vision in our first years were absolutely critical to ESPN's survival," said George Bodenheimer, president of ESPN and ABC Sports. "He was the only industry president to have pioneered both sports broadcasting in the late '50s and cable television in the late '70s."
Simmons influenced or launched the careers of such commentators as Jim Simpson, Merlin Olsen, Greg Gumbel, Bryant Gumbel, Dick Enberg, Curt Gowdy, Tony Kubek, Joe Garagiola, Donna de Varona, Dick Vitale and Jack Buck, among others.
"Chet did so much more than take a chance on us young people 30 years ago," ESPN anchor Chris Berman said. "What you see today would have never been possible without him."
Before going to ESPN, Simmons spent 15 years at NBC, where he was involved in using instant replay and had a hand in attaining the network's major sports properties, including the American Football League, the NFL, Major League Baseball, the NHL, college basketball, the Rose and Orange bowls and Wimbledon.
He joined ESPN as president and chief operating officer July 31, 1979, just before the network's launch Sept. 7.
Among his most notable achievements were the birth and direction of "SportsCenter" on Day 1 of ESPN, providing television's first comprehensive coverage of the early rounds of the men's NCAA basketball tournament and televising the NFL draft (both in 1980).
Simmons left ESPN in 1982 and joined the USFL, serving as the league's commissioner until January 1985.
He went on to serve as a media consultant and adjunct professor at the University of South Carolina.
Simmons was born July 11, 1928, in New York City and earned a bachelor's degree in broadcasting from the University of Alabama.
Survivors include his wife, Harriet, and four children.