Andrews was born Julia Elizabeth Wells (pen name Julie Andrews Edwards) on 1 October 1935 in Walton-on-Thames, Surrey, United Kingdom. Julie had her first non-speaking role as a fairy at age two performing at the dance school of her Aunt Joan (where her mother played piano to pay for her lessons). At three years old she had a singing and speaking role, Nod in a production of Wynken, Blynken, and Nod.

Andrews got her big break when her stepfather introduced her to Val Parnell, whose Moss Empires controlled prominent venues in London. Andrews made her professional solo debut at the London Hippodrome singing the difficult "Je Suis Titania" aria from Mignon as part of a musical revue called "Starlight Roof" on 22 October 1947. She played the Hippodrome for one year. On 1 November 1948, Andrews became the youngest solo performer ever to be seen in a Royal Command Variety Performance, at the London Palladium, where she performed along with Danny Kaye, the Nicholas Brothers, and the comedy team George and Bert Bernard for members of King George VI's family.

Andrews followed her parents into radio and television. She reportedly made her television debut on the BBC program RadiOlympia Showtime on 8 October 1949. She garnered considerable fame throughout England for her work on the BBC radio show "Educating Archie", which she played from 1950 to 1952.

Andrews appeared on West End Theatre at the London Casino, where she played one year each as Princess Balroulbadour in Aladdin and the egg in Humpty Dumpty. She also appeared on provincial stages across England in Jack and the Beanstalk and Little Red Riding Hood, as well as starring as the lead role in Cinderella.

On 30 September 1954, on the eve of her 19th birthday, Andrews made her Broadway debut portraying "Polly Browne" in the already highly successful London musical The Boy Friend. To the critics, Andrews was the stand-out performer in the show. In November 1955, Andrews was signed to appear opposite Bing Crosby in what is regarded as the first made-for-television movie, High Tor.

In 1956, she appeared in the Frederick Loewe and Alan Jay Lerner musical My Fair Lady as Eliza Doolittle, opposite Rex Harrison's Henry Higgins. The show was a musical adaptation of George Bernard Shaw's Pygmalion and became the smash hit of the decade, making Andrews one of the biggest stars of the theatre.

In 1960, Lerner and Loewe again cast her in a period musical, as Queen Guinevere in Camelot, opposite Richard Burton and newcomer Robert Goulet. After a slow start, cast appearances on The Ed Sullivan Show ensured that the show would ultimately become a hit.

Andrews played her first film in the title role of Walt Disney's Mary Poppins. Walt Disney had seen a performance of Camelot and thought Andrews would be perfect for the role of an English nanny who is "practically perfect in every way!" As a result of her performance in Mary Poppins, Andrews won the 1964 Academy Award for Best Actress and the 1965 Golden Globe Award for Best Actress - Motion Picture Musical or Comedy. She and her Mary Poppins co-stars also won the 1965 Grammy Award for Best Album for Children.

In 1964, she appeared opposite James Garnerin The Americanization of Emily (1964), which she has described as her favourite film. In 1966, Andrews won her second Golden Globe Award for Best Actress - Motion Picture Musical or Comedy and was nominated for the 1965 Academy Award for Best Actress for her role as Maria von Trapp in The Sound of Music. The movie also starred actors Christopher Plummerand Eleanor Parker. This governess role had some superficial similarities to that of Mary Poppins.

Andrews starred in her own variety series on the ABC network in 1972 - 1973, winning 7 Emmy Awards. Canceled after one season, Andrews joined the ranks of other musical superstars such as Frank Sinatra, Nat King Cole and Judy Garland.

In 1983, Andrews was chosen as the Hasty Pudding Woman of the Year by the Harvard University theatrical society. The roles of Victoria Grant and Count Victor Grezhinski in the film Victor/Victoria earned Andrews the 1983 Golden Globe Award for Best Actress - Motion Picture Musical or Comedy, as well as a nomination for the 1982 Academy Award for Best Actress, her third Oscar nomination overall.

In the 2000 New Year's Honours, despite Andrews's long exile in the United States and Switzerland, she was made a Dame Commander of the British Empire (DBE). She also appears in the 2002 List of "100 Greatest Britons" sponsored by the BBC and chosen by the public. In 2001, Andrews received Kennedy Center Honors. The same year, she reunited with Sound of Music costar Christopher Plummerin a live television performance of On Golden Pond (an adaptation of the 1979 play).

In 2001, Andrews appeared in The Princess Diaries, her first Disney film since 1964's Mary Poppins. The film, in which she starred as Queen Clarisse Marie Renaldi opposite Anne Hathaway was a box office success and was followed by a sequel, The Princess Diaries 2 (2004). In The Princess Diaries 2, Andrews sang on film for the first time since her throat surgery.

From 2005 to 2006, Andrews served as the Official Ambassador for Disneyland's 18 month-long, 50th anniversary celebration, the "Happiest Homecoming on Earth", travelling to promote the celebration and recording narration or appearing at several events at the park.

In 2004, Andrews performed the voice of Queen Lillian in the animated blockbuster Shrek 2 (2004), reprising the role for its sequel, Shrek the Third (2007). Later in 2007, she narrated Enchanted, a live-action Disney musical comedy that paid homage to classic Disney films such as Mary Poppins.

In January 2007, she was honored with the Lifetime Achievement Award at the Screen Actors Guild's awards, and stated that her goals including continuing to direct for the stage, and possibly to produce her own Broadway musical. She published Home: A Memoir of My Early Years, which she characterized as "part one" of her autobiography, on April 1, 2008. Home chronicles her early years in England's music hall circuit and ends in 1962 with her winning the role of Mary Poppins.