The star, who was also an accomplished stage actor, had been battling a serious lung condition for several years.
Briers died "peacefully" at his London home on Sunday, his agent added.
Briers recently blamed years of smoking for his emphysema.
"It's totally my fault," he said. "So, I get very breathless, which is a pain in the backside. Trying to get upstairs... oh God, it's ridiculous. Of course, when you're bloody nearly 80 it's depressing, because you've had it anyway."
His agent, Christopher Farrar, said: "Richard was a wonderful man, a consummate professional and an absolute joy to work alongside.
"Following his recent discussion of his battle with emphysema, I know he was incredibly touched by the strength of support expressed by friends and the public.
"He has a unique and special place in the hearts of so many. He will be greatly missed. Our thoughts and deepest sympathy go to his family at this sad time."
Briers had a long and successful TV and theatre career
In 1970s BBC sitcom The Good Life, Briers and Felicity Kendal played a married suburban couple who try a self-sufficient lifestyle.
Briers also starred in shows including Marriage Lines, Ever Decreasing Circles, Monarch Of The Glen plus a role in Doctor Who and Torchwood.
Full Article @ BBC