Ella Jane Fitzgerald was born on April 25, 1917, in Newport News, Virginia, to William Ashland Fitzgerald and Temperance Fitzgerald, who were not married. In the early 1920s her mother and her mother's new partner, the Portuguese immigrant Joseph da Silva, moved to Yonkers, New York, where Fitzgerald grew up; her half-sister Frances was born there in 1923. She was raised in a Methodist church community, loved to dance, and listened to records by Louis Armstrong, Bing Crosby, and the Boswell Sisters, copying the phrasing of the Boswells' lead singer, Connee Boswell. Her mother died after a car accident in 1932, and in April 1933 Fitzgerald moved to Harlem to live with an aunt. She stopped going to school, worked with a numbers runner, and was placed in a Bronx orphanage and then a state reformatory in Hudson, New York, before spending 1933 and 1934 getting by in Harlem, partly by singing on the street.

On November 21, 1934, she entered one of the early Amateur Nights at the Apollo Theater, planning to dance, lost her nerve in front of a local dance act, and sang "Judy" and "The Object of My Affection" in Connee Boswell's manner instead, winning first prize. In January 1935 she spent a week with Tiny Bradshaw's band at the Harlem Opera House, and later that year the singer Bardu Ali brought her to the drummer and bandleader Chick Webb, who auditioned her at a Yale dance before hiring her. With Webb's orchestra, closely tied to Harlem's Savoy Ballroom, she made her first Decca records in 1935 and had hits with "Love and Kisses" and "(If You Can't Sing It) You'll Have to Swing It (Mr. Paganini)." Her 1938 setting of the nursery rhyme "A-Tisket, A-Tasket," recorded on May 2 and partly her own writing, reached number one and became one of the best-selling records of the decade. When Webb died of spinal tuberculosis on June 16, 1939, the band was renamed Ella Fitzgerald and Her Famous Orchestra, and she led it until it broke up in 1942.

As a solo artist on Decca she made hits with Bill Kenny and the Ink Spots, among them "I'm Making Believe" and "Into Each Life Some Rain Must Fall" (recorded August 30, 1944), both of which reached number one, and with Louis Jordan and the Delta Rhythm Boys. Her time with Dizzy Gillespie's big band in the mid-1940s pushed her toward bebop and made scat singing a core part of her act; her 1945 recording of "Flying Home" and her 1947 "Oh, Lady Be Good!" became touchstones for singers imitating a horn. Through the Gillespie band she met its bassist, Ray Brown, whom she married in December 1947; they adopted a son, Ray Brown Jr., and divorced in 1953. From 1949 she toured with Norman Granz's Jazz at the Philharmonic, whose contracts barred segregated seating, and Granz became her manager.

Fitzgerald left Decca in 1955, and Granz built Verve Records around her. The label's landmark project was a run of eight Song Book sets recorded from 1956 to 1964, each given to one songwriter: Cole Porter (1956, arranged by Buddy Bregman), Rodgers and Hart, Duke Ellington (1957), Irving Berlin (arranged by Paul Weston), George and Ira Gershwin (1959, arranged by Nelson Riddle), Harold Arlen (Billy May), Jerome Kern, and Johnny Mercer (the last two again with Riddle). The Ellington set is the only one in which the composer performs, with Ellington and Billy Strayhorn playing on about half of its 38 tracks. At the first Grammy Awards ceremony in 1959 she won two awards, for the Ellington and Irving Berlin Song Books. In the same years she made three duet albums with Armstrong for Verve, Ella and Louis (1956), Ella and Louis Again (1957), and Porgy and Bess (1959), and recorded Ella in Berlin on February 13, 1960, at the Deutschlandhalle with a quartet led by pianist Paul Smith and including guitarist Jim Hall. On that night she lost the words to "Mack the Knife" and improvised new lyrics; the album earned two Grammys and entered the Grammy Hall of Fame in 1999. Granz sold Verve to MGM in 1960, MGM did not renew her contract in 1967, and she recorded for Atlantic, Capitol, and Reprise before returning to Granz.

The success of the 1972 live set Jazz at Santa Monica Civic '72, which paired her with the Count Basie Orchestra and a crowd of guests including Stan Getz, led Granz to found Pablo Records, where she made roughly twenty albums. Among them were Ella in London (recorded April 11, 1974, at Ronnie Scott's Club with a quartet of Tommy Flanagan, Joe Pass, bassist Keter Betts, and drummer Bobby Durham); four duo albums with Pass, Take Love Easy (1974), Fitzgerald and Pass... Again (1976), Speak Love (1983), and Easy Living (1986); Ella and Oscar (recorded May 19, 1975, with Oscar Peterson); Digital III at Montreux (July 12, 1979); and Ella Abraça Jobim (1980-81), a bossa nova set of songs by Antonio Carlos Jobim, whom she never worked with directly. Her voice thickened in these years, and illness ended her recording and touring in the early 1990s. She was hospitalized for respiratory trouble in 1985, congestive heart failure in 1986, and exhaustion in 1990; diabetes later cost her both legs below the knee in 1993, the year she set up the Ella Fitzgerald Charitable Foundation. She passed away at her home in Beverly Hills on June 15, 1996, after a stroke, at 79, and was buried at Inglewood Park Cemetery.

Her honors include 13 competitive Grammy Awards, a Grammy Lifetime Achievement Award in 1967, the National Medal of Arts in 1987, and the Presidential Medal of Freedom, along with honorary doctorates from Yale (1986) and Harvard (1990). Her papers and memorabilia are held by the Smithsonian Institution and the Library of Congress.

Fitzgerald is remembered for a pure, light tone, near-perfect diction and intonation, flawless time, and an improvisational gift, strongest in her scat singing, that critics often called horn-like; she said she tried to do with her voice what the horn players in Dizzy Gillespie's band did. Her first model was Connee Boswell, and the years with Chick Webb's orchestra made her a swing singer before bebop widened her phrasing. Her song choices in the Song Books ranged from standards to rarities, and in small-group sets with Oscar Peterson or Joe Pass she kept the same rhythmic precision at any tempo. The New York Times credited the Song Book series, which gave each album to one songwriter, with helping establish the pop album as a vehicle for serious musical exploration, and Ira Gershwin said he never knew how good his and his brother's songs were until he heard her sing them. She was also a civil rights activist; on Granz's Jazz at the Philharmonic tours she was guaranteed equal pay and accommodations regardless of her race or sex. Younger singers have honored her on record, including Dee Dee Bridgewater's Dear Ella (1997), Patti Austin's For Ella (2002), and Ann Hampton Callaway's To Ella with Love (1996).