Joan Greenwood, of the plummy feline voice, was born in the well-to-do London section of Chelsea, the daughter of renowned portrait painter Sydney Earnshaw Greenwood (1887-1949). Dancing from the age of eight, she took ballet lessons and later enrolled at the Royal Academy of Dramatic Art (RADA). Graduating at age 18, Joan made her theatrical debut in 莫里哀's "Malade Imaginaire" at the Apollo Theatre. Performing some time later in 克雷·布斯's "The Women", she was noticed by 莱斯利·霍华德, who cast the diminutive lass as his leading lady in his wartime flag waver 巾帼不让 (1943). From this time onward, Joan began to alternate between stage and screen, comedy and drama. She worked during the London Blitz and toured with the Entertainment National Service Association (ENSA).
The theatre saw her in classical plays with the 唐纳德·沃尔菲 Company, ranging from 萧伯纳's "Heartbreak House" to 莎士比亚's "Hamlet" (as Ophelia), and 易卜生's "Hedda Gabler". On screen she gave a strong, sensitive performance in 埃里克·安卜勒's psychological thriller The October Man (1947). She was also effectively cast opposite 斯图尔特·格兰杰 as the fragile, conflicted Sophie Dorothea, imprisoned in a loveless marriage, in 巴兹尔·迪尔登's period romance 深宫残梦 (1948). Above all, she is fondly remembered for a trio of classic Ealing comedies, conveying a measure of eroticism while remaining quintessentially "correct" and "properly British". She purred her way through 仁心与冠冕 (1949) (as the beguiling, but manipulative Sibella) and as Scottish Peggy Macroon she taunted straight-laced 巴西尔·拉德福德 in 荒岛酒池 (1949). She was Lady Caroline Lamb in The Bad Lord Byron (1949) and she dutifully undermined idealistic, naive inventor Sidney Stratton (亚历克·吉尼斯) in 白衣男子 (1951).
In between her two other major screen roles--Gwendolen Fairfax in 贵在真诚 (1952) and lascivious Lady Bellaston in 汤姆·琼斯 (1963)--Joan had a brief spell in Hollywood, paired again with Stewart Granger for 弗里茨·朗's gothic period melodrama 慕理小镇 (1955). She did not enjoy the experience. Eschewing the trimmings of Hollywood stardom, she opted instead for the uncomplicated life at Ealing, where actors "washed their hair in buckets" and lived on "toasted sandwiches, chocolates and soup".
Joan Greenwood died of a heart attack on February 28, 1987, less than a week before her 66th birthday.