She succeeded Lord Olivier as president of the Actors' Benevolent Fund after his death in 1989, and was appointed Dame Commander of the Order of the British Empire (DBE) in the 2014 New Year Honours for services to the arts and to charity.

[1] Keith joined the Royal Shakespeare Company in 1963, and went on to win the 1976 Olivier Award for Best Comedy Performance for the play Donkeys' Years.

She became a household name in the UK playing Margo Leadbetter in the sitcom The Good Life (1975–78), winning the 1977 BAFTA TV Award for Best Light Entertainment Performance.

Since 2000, she has worked mainly in the theatre, with her roles including Madam Arcati in Blithe Spirit (2004) and Lady Bracknell in The Importance of Being Earnest (2007).

[2] Her father, an army officer who was a Major by the end of the Second World War, left her mother, Connie, when Keith was a baby, and she spent her early years in Clacton-on-Sea, Essex and Clapham, south London.

However she was then accepted at the Webber Douglas Academy of Dramatic Art and spent two years there while working at the Hyde Park Hotel in the evenings.

Her best known theatre appearance, in 1974, was playing Sarah in The Norman Conquests, alongside Felicity Kendal, her co-star in The Good Life.

[citation needed] In 1977 Keith starred in Brian Sibley's comedy radio broadcast titled ...And Yet Another Partridge in a Pear Tree,[10][11] voicing a woman named Cynthia Bracegirdle whose boyfriend, Algernon Fotherington-Smythe, sends her the 364 gifts mentioned in The Twelve Days of Christmas.

Following To the Manor Born, Keith has appeared in the lead role in six other sitcoms: Sweet Sixteen, Moving, Executive Stress, No Job for a Lady, Law and Disorder and Next of Kin.

[citation needed] In 2007, she starred in a one-off To the Manor Born Christmas Special, Keith also voiced The Bear with Brown Fuzzy Hair in Teletubbies.

[citation needed] In 2009 she presented Penelope Keith and the Fast Lady, a one-off documentary for BBC Four about Dorothy Levitt, the Edwardian motoring pioneer.

[19] In 2013 she played the part of Lady Catherine de Bourgh in the BBC period drama Death Comes to Pemberley, an adaptation of the best-selling 2011 P. D. James novel of the same name.

It was announced in February 2018 that Keith would be starring as Mrs St Maugham in the Chichester Festival Theatre production of Enid Bagnold's The Chalk Garden from 25 May to 16 June 2018.

[citation needed] On 2 April 2002, her 62nd birthday, Keith began a one-year term as High Sheriff of Surrey,[27] the third woman to hold the post.