Wagoner was hospitalized Oct. 15, and was transferred Friday from the hospital to hospice care. He died Sunday night, The Nashville Tennessean reported.
Wagoner -- a member of the Grand Ole Opry for 50 years -- began his career with the Blue Ridge Boys singing on a Missouri radio station, and starred in "The Porter Wagoner Show" on TV from 1960 to 1979. Another country music icon, Dolly Parton, became an international star during her seven years on the show.
Wagoner's long list of country hits included "A Satisfied Mind," "Misery Loves Company" and "Green, Green Grass of Home."
A member of the Country Music Hall of Fame and a three-time Grammy winner, Wagoner suffered a near-fatal stomach aneurysm in 2006.
He released a new album this year, "Wagonmaster," to critical raves. He promoted the project by appearing with such contemporary acts Neko Case in Hollywood and the White Stripes at New York's Madison Square Garden.
Wagoner is survived by three children, Richard, Debra and Denise, the Tennessean said.