His manager Alan Mills said he was taken aback at the actor's death because Waite, who lived in the Palm Springs area of California, had been in good health and still working.
Waite appeared last year in episodes of the series NCIS, in which he played the father of star Mark Harmon's character. He also appeared in Bones and Days Of Our Lives.
The Waltons, shown on CBS from 1972 to 1981, starred Waite as John Walton, and Richard Thomas played his oldest son, John-Boy, an aspiring novelist. The gentle family drama was set in the Blue Ridge mountains of Virginia.
His co-stars praised both the actor and the man today.
"I am devastated to announce the loss of my precious 'papa' Walton, Ralph Waite," said Mary McDonough, who played daughter Erin Walton. "I loved him so much; I know he was so special to all of us. He was like a real father to me. Goodnight Daddy. I love you."
Michael Learned, who played wife Olivia Walton, said she was "devastated" by the death of "a good honest actor and a good honest man".
"He was my spiritual husband," Learned said. "We loved each other for over 40 years. He died a working actor at the top of his game. He was a loving mentor to many and a role model to an entire generation."
The show, which followed the Waltons' triumphs and setbacks through the Great Depression and the Second World War, was narrated by its creator Earl Hamner, who based it on his family memories.
It was a TV rarity, a respectful depiction of Southern country life, and proved so popular that it overpowered its hit comedy competition, NBC's The Flip Wilson Show.
Waite, a native of White Plains, New York, served in the US Marines before earning a bachelor's degree from Bucknell University and a master's degree from Yale University Divinity School, according to a 2010 profile by The Desert Sun.
He became an ordained Presbyterian minister and then worked at a publishing house, the paper said, before falling under the spell of acting. Waite appeared on the stage before moving on to the big screen with roles in 1967's Cool Hand Luke and 1970's Five Easy Pieces, in which he played the brother of Jack Nicholson's character.
Waite received an Emmy nomination for The Waltons and another for his performance in the ABC mini-series Roots.
But his role as a steady TV dad in the CBS drama was in contrast to his personal life that was undercut by alcoholism, Waite told The Desert Sun.
"I was a caring, responsible father to all of these kids. But I was drinking the night before and being a drunk on the side," he said, adding: "I found a way to get sober."
In 1990 Waite ran unsuccessfully as the Democratic challenger to a four-term Republican incumbent for the congressional district that included Riverside, Palm Springs and Palm Desert, where Waite lived.
In 1998, he vied for the congressional seat left open after Republican Sonny Bono, another performer who turned to politics, died in a skiing accident. Bono's widow, Mary, won the special election.