The Surrey-born actress joined the Royal Shakespeare company in 1963 and went on to win an Olivier Award for best comedy performance in 1976, for her role in the play Donkey’s Years.
But she became a household name playing Margo in The Good Life from 1975, winning the Bafta TV award for best light entertainment performance in 1977.
She followed that by playing widowed aristocrat Audrey fforbes-Hamilton in To the Manor Born, which first aired in 1979.
She won another Bafta TV award soon after, this time for best actress for The Norman Conquests and Saving It For Albie.
Her other sitcom credits in the 1980s and 90s included Executive Stress, No Job for a Lady and Next of Kin.
The much-loved actress succeeded Laurence Olivier as president of the Actors’ Benevolent Fund after his death in 1989.
This century, working largely in theatre, she played Madame Arcati in a 2004 production of Blithe Spirit and Lady Bracknell in a 2007 version of The Importance of Being Earnest.
She was a made a dame in 2014 for services to the arts and charity.
Former culture secretary Sir Jeremy Hunt led the tributes, posting on X: “Incredibly sad to hear of the passing of Dame Penelope Keith CBE. She was a neighbour and friend where she was dearly loved by all who knew her in Milford.
“She helped Britain laugh at itself, one of our best national qualities, and brought happiness to millions. RIP dear Penny.”