Bennett Lester Carter was born on August 8, 1907, in New York City. His mother and neighborhood teachers gave him piano lessons, and he took up the trumpet, tried a C-melody saxophone, and settled on the alto saxophone, teaching himself most of what he knew. In the 1920s he worked in bands led by June Clark, Billy Paige and Earl Hines, then toured with the Wilberforce Collegians under Horace Henderson, and became the group's leader, holding that role through 1929. His first records came in 1927 with Charlie Johnson's Paradise Ten. While still in his early twenties he became arranger for Fletcher Henderson's orchestra after Don Redman left, learning to write by trial and error, and in 1930 he wrote "Keep a Song in Your Soul" for the band; he worked with Henderson until 1931.

He then succeeded Redman as musical director of McKinney's Cotton Pickers in Detroit and in 1932 formed a band of his own in New York that drew on players such as Chu Berry, Sid Catlett, Frankie Newton, Dicky Wells and Wayman Carver, with Teddy Wilson joining in 1933 according to Wilson's own profile. The orchestra made only a handful of records, for Columbia, OKeh and Vocalion, the OKeh sides appearing as the Chocolate Dandies, and its scores, among them "Lonesome Nights" and "Symphony in Riffs" (both 1933), became models of saxophone-section writing. In 1933 members of his band also took part in the New York sessions organized by the British arranger Spike Hughes, which were first issued only in England. Carter was by then ranked with Johnny Hodges as one of the two leading altoists in jazz, and he had also become a leading trumpet soloist.

In 1935 he moved to Europe. He was a staff arranger for the BBC's dance orchestra in London from 1936 to 1938, recorded with local musicians in England, France and Scandinavia, led a multiethnic band in Scandinavia in 1937, and took a group to the Netherlands, playing trumpet, clarinet, piano and saxophones in these settings. In Paris he joined Coleman Hawkins, Django Reinhardt and others on a 1937 session billed to Hawkins's All-Star Jam Band, and in 1938 he recorded with Reinhardt again on "I'm Coming Virginia" and "Farewell Blues." Back in the United States in 1938, he led a band at Harlem's Savoy Ballroom through 1941 whose players included Shad Collins, Sidney De Paris, Vic Dickenson and Freddie Webster, followed by a seven-piece group with Eddie Barefield, Kenny Clarke and Dizzy Gillespie.

By the mid-1940s Carter was based in Los Angeles. He led a big band there that at times included J.J. Johnson, Max Roach and Miles Davis, and in which Carmen McRae sang in 1944; he soon gave up touring with big bands, though Tommy Turrentine was in his orchestra from 1946 to 1948 and Art Farmer also played and toured with him. Studio work now dominated his time. His first film credit was the 1943 picture Stormy Weather, and he went on to write for Thousands Cheer (1943), An American in Paris (1951), Clash by Night and The Snows of Kilimanjaro (both 1952) and Buck and the Preacher (1972), becoming one of the first African Americans employed in film and television scoring. He kept recording and touring as a player with Norman Granz's Jazz at the Philharmonic and made the Norgran albums Alone Together and Cosmopolite, the first with an Oscar Peterson quartet, as well as a trio session in June 1954 with Art Tatum and drummer Louis Bellson and the August 1955 Music for Torching date with Billie Holiday. He also wrote arrangements for Louis Armstrong, Ray Charles, Ella Fitzgerald, Peggy Lee and Sarah Vaughan, among others, and by the mid-1960s he was writing so much that he rarely played alto. His 1942 song "Cow-Cow Boogie," written with Don Raye and Gene de Paul, was a hit for Ella Mae Morse.

His own records in these years included Further Definitions, recorded in 1961 for Impulse! with Hawkins, Phil Woods, Charlie Rouse and others, an octet of four saxophones and a rhythm section. From the 1970s he returned to full-time playing, toured the Middle East for the U.S. State Department, and made annual visits to Europe and Japan, recording for Pablo with Gillespie (Carter, Gillespie, Inc., April 27, 1976, with Tommy Flanagan and Joe Pass) and with Peterson (Benny Carter Meets Oscar Peterson, 1986). He also became a teacher: after a weekend at Princeton University in 1969 at the invitation of the sociologist Morroe Berger, he visited the school repeatedly, spent a semester there as a visiting professor in 1973, received an honorary doctorate from it in 1974, and lectured at Harvard for a week in 1987. Berger's two-volume Benny Carter: A Life in American Music appeared in 1982.

He kept writing for large forces in his seventies and eighties, among them Central City Sketches, recorded in 1987 with the American Jazz Orchestra, the Glasgow Suite, Good Vibes, a 1990 Lincoln Center commission, and the Harlem Renaissance Suite, performed in 1992 when he was 85. In November 1986 he recorded Billy Eckstine Sings with Benny Carter for Verve, with Billy Eckstine, whose last album it was, and in 1996 he released Songbook for MusicMasters, with guest singers including Dianne Reeves, Diana Krall, Shirley Horn, Jon Hendricks, Marlena Shaw and Peggy Lee. He passed away at Cedars-Sinai Medical Center in Los Angeles on July 12, 2003, at the age of 95, from complications of bronchitis. His honors include the DownBeat Jazz Hall of Fame (1977), the Black Filmmakers Hall of Fame (1978), a National Endowment for the Arts Jazz Masters award (1986), a Grammy Lifetime Achievement Award (1987), a Grammy in 1994 for his solo on "Prelude to a Kiss," a star on the Hollywood Walk of Fame, Kennedy Center Honors (1996) and the National Medal of Arts (2000), presented by President Bill Clinton, along with honorary doctorates from Princeton, Rutgers, Harvard and the New England Conservatory.

Carter is remembered as one of the two pioneers of the jazz alto saxophone alongside Johnny Hodges, with a tone known for its purity, elegant ornamentation and rhythmic precision. His style changed slowly over seven decades without going stale; AllMusic's Scott Yanow wrote that he was as strong an altoist at 90 as he had been at 28. He was equally important as a writer. His scores for Fletcher Henderson's band and for his own orchestra helped define swing-era writing for the saxophone section, "Waltzing the Blues" was among the first jazz waltzes, and in Los Angeles he brought the same craft to film studios and to albums for singers. He also recorded on clarinet, tenor and soprano saxophone, trombone and piano, and he is one of the few musicians to have recorded in eight different decades. Altoists who took in his playing include Phil Woods, who named his records as an early influence, and Art Pepper, whose early manner Britannica ties to Carter; Dmitry Baevsky has named Carter among his deepest influences, and Roberta Gambarini was introduced to the New York jazz community by Carter in 1999. His music belongs to the Swing, Big Band and Mainstream Jazz traditions rather than to any later school.