Dame Edith Louisa Sitwell DBE was born on 7 September 1887 in Scarborough in the North Riding of Yorkshire.

Edith was the oldest child and only daughter of her wildly eccentric and unloving parents. Her father, believing she had a spinal deformation, imposed upon her a ‘cure’ which involved locking her into an iron frame.  In 1913 Edith began to publish her poetry, her first was in the Daily Mirror; The Drowned Suns. Unconventional at best as a person her poems reflect this with her exotic costumes and dramatic style all hung on a six foot frame: many adored her, others thought her a poseur.  In 1914, the 26-year-old Edith moved to a small, down at heel flat in Bayswater, which she shared with Helen Rootham, her governess since 1903.  Between 1916 and 1921 she edited Wheels, an annual poetic anthology compiled with her brothers — a literary collaboration generally called "the Sitwells". Edith was engrossed by the distinction between poetry and music, and with Façade (1922), she created a series of abstract poems, the rhythms of which counter-parted those of music, set to music by William Walton. Façade was performed behind a curtain with a hole in the mouth of a painted face and the words were recited through the hole with the aid of a Sengerphone. The public were baffled by it.

Edith spent her life unmarried, but in 1927 it is said she fell in love with the homosexual Russian painter Pavel Tchelitchew. The relationship lasted until 1928, the same year that Rootham underwent operations for cancer.  In 1929 she published Gold Coast Customs, a poem about the artificiality of human behaviour and the barbarism that lies beneath the surface. The poem was written in the rhythms of tom-toms and jazz.  In 1932, Rootham and Edith moved to Paris, where they lived with Rootham's younger sister, Evelyn Wiel.

With the Second World War Edith returned from France.  In a house with no electricity she wrote by oil lamp. These poems include Street Songs, The Song of the Cold, and The Shadow of Cain, all of which garnered much public praise. However the London blitz poem "Still Falls the Rain" endures as her best loved poem. It was set to music by Benjamin Britten.

She became a proponent and supporter of innovative trends in English poetry. Her flat became a meeting place for young writers including Dylan Thomas.

In 1948 Edith toured the United States with her brothers, reciting her poetry and, notoriously, giving a reading of Lady Macbeth's sleepwalking scene.

Edith became a Dame Commander (DBE) in 1954. In August 1955 she converted to Roman Catholicism.

As a writer Edith claimed to only write prose for money and with titles such as English Eccentrics (1933), Victoria of England (1936), her novel, I Live under a Black Sun, based on the life of Jonathan Swift (1937) and two books about Queen Elizabeth I: Fanfare for Elizabeth (1946) and The Queens and the Hive (1962) she was very successful at that.

Edith lived from 1961 until her death in a flat in Hampstead in London. As the subject of This Is Your Life in November 1962 she was surprised by host Eamonn Andrews on the stage of the BBC Television Theatre in London.  Edith died of cerebral haemorrhage at St Thomas' Hospital on 9 December 1964 at the age of 77.

She is buried in the churchyard of Weedon Lois in Northamptonshire.