His suspected cause of death is respiratory failure, after he was battling an intestinal issue since 2016.
Born Lonnie Melvin Tillis in Tampa, Florida in 1932, Tillis caught malaria as a child, leaving him with a speech impediment for which he was mocked in his youth but which he embraced as an adult, incorporating it into his performances for comic effect.
In 1976, Tillis won the Country Music Association's Entertainer of the Year award and was inducted in the Nashville Songwriter's Hall of Fame. Besides being a successful recording artist, Tillis performed at the Grand Ole Opry and made frequent television appearances, as well as playing small roles in movies such as Smokey and the Bandit II and The Cannonball Run.
In all, the Country Music Hall of Fame member wrote more than 1,000 songs and in 2012 received a National Medal of Arts for bringing "his unique blend of warmth and humor to the great tradition of country music".
He joined the U.S. Air Force and was stationed as a baker in Okinawa, where he formed a band called the Westerners.
His commercial peak came in the 1970s when he had a string of top 10 hits, including "Good Woman Blues", "Heart Healer" and "Coca Cola Cowboy".
Tillis was also an actor, and appeared in several feature films. Among the hits he wrote for others were "Detroit City" for Bobby Bare; "Ruby, Don't Take Your Love to Town", by Rogers and the First Edition; and "Thoughts of a Fool" for George Strait. He also briefly co-hosted an ABC prime-time series, "Mel and Susan Together", with supermodel Susan Anton in 1978.