Joanna Lamond Lumley was born on 1 May 1946 in Srinagar, in the princely state of Jammu and Kashmir. Her parents were Major James Rutherford Lumley, who served in the 6th Gurkha Rifles, a regiment of the Indian Army, and Beatrice Rose Weir. They married in 1941. After the independence of India in 1947, the Lumleys moved to Malaya (now Malaysia) and later settled in Kent, England. Lumley was educated at St Mary's School in Hastings, East Sussex, England, and afterwards attended the Lucy Clayton School of modelling.

Tall, slim and blonde, she spent three years as a photographic model, notably for Brian Duffy by whom she was photographed with her son. She also worked as a house model for Jean Muir. Over forty years later she participated in another photoshoot - again with her son - for Duffy as part of a retrospective of the photographer's work.

Lumley appeared in an early episode of The Bruce Forsyth Show in 1966. She appeared in a UK television advertisement for Nimble bread first screened in 1969.

Lumley did not receive any formal training at drama school. Her acting career began in 1969 with a small role in the film Some Girls Do and as a Bond girl in On Her Majesty's Secret Service; she played the English girl among Blofeld's 'Angels of Death' and had two lines. She went on to have a brief but memorable role in Coronation Street, in which her character turned down Ken Barlow's offer of marriage.

In the Are You Being Served? episode "His and Hers" (season 1; episode 4), she was featured as Miss French, a perfume representative. In the episode "German Week" (season 3; episode 6), she appeared as "German Lady". She also appeared on the big screen in The Satanic Rites of Dracula, released 13 January 1974, starring Peter Cushing and Christopher Lee. She also appeared in Steptoe & Son in the episode "Loathe Story".

Throughout her career, she has specialised in playing upper-class parts, and her distinctive plummy voice has reinforced this. Lumley's first major role was as Purdey in The New Avengers, a revival of the secret agent series The Avengers. Although critical reaction to the series was lukewarm, the casting of Lumley was seen as inspired and following the tradition of iconic Avengers actresses Honor Blackman, Diana Rigg and Linda Thorson.

In 1979 she appeared in another series which acquired a following: Sapphire and Steel, with David McCallum. Conceived as ITV's answer to Doctor Who, Lumley played a mysterious elemental being ('Sapphire') who, with her collaborator 'Steel', dealt with breaches in the fabric of time.

Over a decade later, Lumley's career was boosted by her portrayal of the louche, solipsistic and frequently drunken fashion director Patsy Stone, companion to Jennifer Saunders' Edina Monsoon in the BBC comedy television series Absolutely Fabulous (1992–1996) and (2001–2004).

Other work has included: Lovejoy as widow Victoria Cavero, a film about a journey made by her grandparents in Bhutan - In the Kingdom of the Thunder Dragon (1996) - and A Rather English Marriage (nominated for a BAFTA for Best Actress 1999) and Dr Willoughby (1999). In 1995 she provided the voice of Annie the rag doll in the animated series The Forgotten Toys. In 1999 she also provided the voice for Sims the chicken in the BAFTA award winning animated series The Foxbusters. In 2000 she co-produced a new drama series The Cazalets. She has also appeared in a TV series on Sarawak, where she spent time in her childhood. She has demonstrated her ability to go beyond stereotypical images, most notably in the monologue series of playlets Up In Town (2002), written by Hugo Blick, and focusing on a society hostess's realisation that her star is fading.

Lumley stars as the elderly Delilah Stagg in the 2006 sitcom Jam & Jerusalem with Dawn French, Jennifer Saunders and Sue Johnston. In July 2007 she starred in the second series of the drama Sensitive Skin where she played the main character Davina Jackson. The BBC has said this will be the final series of the dark comedy.