Hayes, a member of the Rock and Roll Hall of Fame and an Oscar- and Grammy-winning singer, composer and producer, was found unconscious next to a treadmill at his home about 1 p.m., The Commercial-Appeal newspaper in Memphis reported. Family members found him when they returned home from a shopping trip and called 911.
He was taken to Baptist Memorial Hospital, where he was pronounced dead just after 2 p.m. A sheriff's office spokesman said a routine investigation would be conducted but there was no indication of foul play.
Hayes was born Aug. 20, 1942, in Covington, Tenn. With David Porter, he composed hits for Carla Thomas, Johnnie Taylor and Sam & Dave, who had hits with his tunes "Soul Man" and "Hold on I'm Comin.'"
He had success as a recording artist with the 1969 album "Hot Buttered Soul" and then won an Oscar and two Grammys in 1971 for his music for the movie "Shaft."
Hayes also enjoyed success as an actor, with a long-running role as Chef in the TV comedy "South Park" and roles in the movies "Escape from New York" and "I'm Gonna Git You Sucka."
He recently completed filming on "Soul Men," starring Samuel L. Jackson and Bernie Mac -- who died Saturday at 50 -- as former singing partners.
Hayes was inducted into the Rock and Roll Hall of Fame in 2002. He was inducted into the Songwriters Hall of Fame in 2005.