[1] Lanchester studied dance as a child and after the First World War began performing in theatre and cabaret, where she established her career over the following decade.

Following Laughton's death in 1962, Lanchester resumed her career with appearances in such Disney films as Mary Poppins (1964), Pajama Party (1964), That Darn Cat!

[2] Her parents, James "Séamus" Sullivan (1872–1945) and Edith "Biddy" Lanchester (1871–1966), were Bohemians, and refused to marry in a religious or legal way as a rebellion against Edwardian era society.

Elsa's older brother, Waldo Sullivan Lanchester, born five years earlier, was a puppeteer, with his own marionette company based in Malvern, Worcestershire, and later in Stratford-upon-Avon.

At that point (she was about twelve years of age) she began teaching dance in the Duncan style and gave classes to children in her south London district, through which she earned some welcome extra income for her household.

[citation needed] After World War I, Lanchester started the Children's Theatre, and later the Cave of Harmony, a nightclub at which modern plays and cabaret turns were performed.

[6] Her cabaret and nightclub appearances led to more serious stage work and it was in a play by Arnold Bennett called Mr Prohack (1927) that Lanchester first met another member of the cast, Charles Laughton.

[6]Lanchester made her film debut in The Scarlet Woman (1925) and in 1928 appeared in three silent shorts written for her by H. G. Wells and directed by Ivor Montagu: Blue Bottles, Daydreams and The Tonic.

They also appeared together in a 1930 film revue entitled Comets, featuring British stage, musical and variety acts, in which they sang in duet "The Ballad of Frankie and Johnnie".

She and Laughton played husband and wife (their characters were named Charles and Elsa Smith) in Tales of Manhattan (1942) and they both appeared again in the all-star, mostly British cast of Forever and a Day (1943).

Lanchester played a comical role as an artist in the thriller, The Big Clock (1948), in which Laughton starred as a megalomaniacal press tycoon.

[8] Here she performed her solo vaudeville act in conjunction with a marionette show, singing somewhat off-colour songs which she later recorded for a couple of LPs.

[9][10] Onscreen, she appeared alongside Danny Kaye in The Inspector General (1949), played a blackmailing landlady in Mystery Street (1950), and was Shelley Winters's travelling companion in Frenchie (1950).

Lanchester played the role of Aunt Queenie, a witch in Bell, Book and Candle (1958), and appeared in such films as Mary Poppins (1964), in which her husband's goddaughter Karen Dotrice also starred, That Darn Cat!

She claimed Laughton had told her that the reason he and his wife never had children was because of a botched abortion Lanchester had early in her career when performing burlesque.

[19] Lanchester died in Woodland Hills, Los Angeles, California, on 26 December 1986, aged 84, at the Motion Picture Hospital from bronchial pneumonia.