Dillard died Wednesday, a publicist said.
With his brother Rod, Douglas Flint Dillard was part of The Dillards, a top-tier bluegrass band that helped popularize the genre in the 1960s and was inducted into the Bluegrass Hall of Fame in 2009.
The Dillards made regular appearances on television's "The Andy Griffith Show" as The Darlings, with Griffith -- as Sheriff Andy Taylor -- frequently sitting in with the group. They have been credited with laying the groundwork for the development of country rock music, the Los Angeles Times said.
"I would put him at the very top level of proficiency on the banjo, right up there with Earl Scruggs," Chris Hillman, a founding member of the Byrds and the Flying Burrito Brothers, told the Times. "He was a great musician, and he greatly influenced me."
Scruggs was a great influence on Dillard, who as a teenager wrote letters to Scruggs, and eventually helped incorporate early 1950s rock-and-roll into the Dillards' bluegrass sound.
"Doug Dillard was a banjo icon," actor and banjo man Steve Martin said in a written statement. "He, along with his group, the Dillards, influenced so many players ... . He was fast, clean and a melodic player with his own style."
John McEuen, founding member of The Nitty Gritty Dirt Band, called Dillard a mentor, "who showed me that music was exciting and fun to play on stage for people," and said Dillard's "grin would hit the back of the wall from any stage he was on."
"I am grateful to have been able to call Dillard a friend," McEuen said in a statement. "There would not have been a Nitty Gritty Dirt Band with me in it if it had not been for Doug."