Julie Christie was born in Chabua, Assam, India, then part of the British Empire, the first of two children of Rosemary (née Ramsden) and Frank St. John Christie.

Christie's mother was a Welsh-born painter and childhood friend of actor Richard Burton, while Christie's father ran the tea plantation around which Christie grew up. She had a brother and a half-sibling from her father's affair with an Indian mistress.

Christie's parents separated during her childhood. She was baptized in the Anglican church and studied as a boarder at Convent of Our Lady School in St Leonards-on-Sea, East Sussex (from which she was later expelled), and then at Wycombe Court School in High Wycombe, Buckinghamshire, also living with a foster mother from the age of six.

After her parents' divorce, Christie spent time with her mother in rural Wales. As a teenager at Wycombe Court School, she played the role of the Dauphin in a school production of George Bernard Shaw's "St. Joan". She later studied at the Central School of Speech and Drama before getting her big break in 1961 in a science fiction series on BBC television, entitled A for Andromeda.

Christie's first major film role was in The Fast Lady, a 1962 romantic comedy. Her breakout role was as Liz, the friend and would-be lover of the eponymous Billy Liar played by Tom Courtenay in the 1963 film directed by John Schlesinger.

Schlesinger, who only cast Christie after another actress dropped out of his film, directed her in her breakthrough role, as the amoral model Diana Scott in Darling (1965), a role which the producers originally offered to Shirley MacLaine. Though virtually unknown before Darling, Christie ended the year 1965 by appearing as Lara Antipova in David Lean's adaptation of Boris Pasternak's novel Doctor Zhivago (1965), which was one of the all-time box office hits, and as Daisy Battles in Young Cassidy, the John Ford-Jack Cardiff directed biopic of Irish playwright Sean O'Casey.

In 1966, the 25-year-old Christie was nominated for a BAFTA Award for Best Actress in a Leading Role when she played a double role in Francois Truffaut's Fahrenheit 451 and won the Academy Award for Best Actress and BAFTA Award for Best Actress in a Leading Role for Darling. Later, she played Thomas Hardy's heroine Bathsheba Everdene in Schlesinger's Far from the Madding Crowd (1967) and the lead character, Petulia Danner, (opposite George C. Scott) in Richard Lester's Petulia (1968).

In the 1970s, Christie starred in such films as Robert Altman's McCabe & Mrs. Miller (1971) (her second Best Actress Oscar nomination), The Go-Between (again co-starring Alan Bates, 1971), Don't Look Now (1973), Shampoo (1975), Altman's classic Nashville (also 1975, in an amusing cameo as herself opposite Karen Black and Henry Gibson), Demon Seed (1977), and Heaven Can Wait (1978).

She moved to Hollywood during the decade, where she had a high-profile (1967-1974), but intermittent relationship with actor Warren Beatty who described her as "the most beautiful and at the same time the most nervous person I had ever known".

Following the end of the relationship, she returned to the United Kingdom, where she lived on a farm in Wales. Never a prolific actress, even at the height of her fame and bankability in the 1960s, Christie made fewer and fewer films in the 1980s.

She had a major supporting role in Sidney Lumet's Power (1986), but other than that, she avoided appearances in large budget films and appeared in riskier fare. She narrated the 1981 documentary The Animals Film (directed by Myriam Alaux and Victor Schonfeld).

Christie has turned down many leading roles in films such as They Shoot Horses, Don't They?, Anne of the Thousand Days and The Greek Tycoon. Christie also signed on to play the female lead in American Gigolo opposite Richard Gere, however when Gere dropped out and John Travolta was cast in the role, Christie too dropped out from the project.

Gere changed his mind and took back the role, however it was too late for Christie as her part was already taken by Lauren Hutton. Julie Christie also had to drop out of the leading role in Agatha due to breaking her wrist whilst roller-skating; the part was filled by Vanessa Redgrave.