Briers' agent told the BBC that he died "peacefully" at his home in London. He had been battling a serious lung condition for several years. In interviews, Briers blamed years of smoking for his emphysema.
A London native, Briers' first claim to fame was playing George Starling in the TV series Marriage Lines, which ran from 1961 to 1966. However, it was his turn as Tom in the 1975 BBC sitcom The Good Life, about a draughtsman who decides on his 40th birthday to quit his job and try his hand at self-sufficiency, that made him a household name. The show's final episode was performed in front of the Queen.
He enjoyed several leading TV roles during the 1980s and 1990s, including Ever Decreasing Circles, If You See God, Tell Him, and Down to Earth. In recent years, he had guest-starred on Extras and Torchwood, and also played the servant Adam in Kenneth Branagh's 2006 adaptation of Shakespeare's As You Like It.
In 1989, Briers was named an Officer of the British Empire, and in 2003, he was named a Commander of the British Empire.
Briers is survived by his wife, Ann Davies, and their two daughters, Lucy and Katie.