Adeline Virginia Woolf (; née Stephen; 25 January 1882 – 28 March 1941) was an English writer, considered one of the most important modernist 20th-century authors and also a pioneer in the use of stream of consciousness as a narrative device.

Woolf was born into an affluent household in South Kensington, London, the seventh child in a blended family of eight. Her mother, Julia Prinsep Jackson, celebrated as a Pre-Raphaelite artist's model, had three children from her first marriage, while Woolf's father, Leslie Stephen, a notable man of letters, had one previous daughter. The Stephens produced another four children, including the modernist painter Vanessa Bell. While the boys in the family received college educations, the girls were home-schooled in English classics and Victorian literature. An important influence in Virginia Woolf's early life was the summer home the family used in St Ives, Cornwall, where she first saw the Godrevy Lighthouse, which was to become central in her novel To the Lighthouse (1927).

Woolf's childhood came to an abrupt end in 1895 with the death of her mother and her first mental breakdown, followed two years later by the death of her stepsister and a mother figure to her, Stella Duckworth. From 1897 to 1901, she attended the Ladies' Department of King's College London, where she studied classics and history and came into contact with early reformers of women's higher education and the women's rights movement. Other important influences were her Cambridge-educated brothers and unfettered access to her father's vast library.

Encouraged by her father, Woolf began writing professionally in 1900. Her father's death in 1905 caused another mental breakdown for Woolf. Following his death, the Stephen family moved from Kensington to the more bohemian Bloomsbury, where they adopted a free-spirited lifestyle. It was in Bloomsbury where, in conjunction with the brothers' intellectual friends, they formed the artistic and literary Bloomsbury Group.

Following her 1912 marriage to Leonard Woolf, the couple founded the Hogarth Press in 1917, which published much of her work. The couple rented a home in Sussex and moved there permanently in 1940. Throughout her life, Woolf was troubled by her mental illness. She was institutionalized several times and attempted suicide at least twice. Her illness is considered to have been bipolar disorder, for which there was no effective intervention during her lifetime. At age 59, Woolf committed suicide in 1941 by putting rocks in her coat pockets and drowning herself in the River Ouse.

During the interwar period, Woolf was an important part of London's literary and artistic society. In 1915 she published her first novel, The Voyage Out, through her half-brother's publishing house, Gerald Duckworth and Company. Her best-known works include the novels Mrs Dalloway (1925), To the Lighthouse (1927) and Orlando (1928). She is also known for her essays, including A Room of One's Own (1929), in which she wrote the much-quoted dictum, "A woman must have money and a room of her own if she is to write fiction."

Woolf became one of the central subjects of the 1970s movement of feminist criticism and her works have since garnered much attention and widespread commentary for "inspiring feminism." Her works have been translated into more than 50 languages. A large body of literature is dedicated to her life and work, and she has been the subject of plays, novels and films. Woolf is commemorated today by statues, societies dedicated to her work and a building at the University of London.