Stanley Newcomb Kenton was born December 15, 1911, in Wichita, Kansas. Because he was born out of wedlock, his parents Floyd and Stella told him his birthday was February 19, 1912, and he believed the false date his whole life; his grave marker still carries it, and the December 1911 date was established later by the British Kenton biographer Michael Sparke. The family moved to Colorado and then, in 1924, to Bell, California, where Kenton attended Bell High School and was tagged in the yearbook as "Old Man Jazz." Around age fifteen the pianist Ralph Yaw introduced him to the records of Louis Armstrong and Earl Hines. At sixteen he was playing solo piano in a local hamburger restaurant for fifty cents a night plus tips and leading a group called the Bell-Tones. After graduating in 1930 he worked speakeasies around San Diego and Las Vegas, played with the Francis Gilbert territory band in 1932 and the Everett Hoagland Orchestra in 1933 (which brought him to the Rendezvous Ballroom in Balboa, California, for the first time), joined Gus Arnheim's orchestra in April 1936, cut his first recordings as a sideman with Arnheim in the summer of 1937 (fourteen sides for Brunswick), and spent part of 1938 in Vido Musso's band.

Kenton formed his own orchestra in 1940 and put it on the stand at the Rendezvous Ballroom through the summer of 1941, with Howard Rumsey on bass and Chico Alvarez on trumpet. Early Decca sides sold poorly. The band made its first New York appearance at the Roseland Ballroom in February 1942, and a 1943-44 stretch as the house band on Bob Hope's radio show went badly enough that Les Brown replaced him. What turned it around was a Capitol Records contract in late 1943 and the hit "Eager Beaver." Art Pepper and, briefly, Stan Getz passed through the reed section, and Anita O'Day sang with the band before June Christy replaced her in 1945. That same year Pete Rugolo became Kenton's chief arranger and brought Stravinsky and Bartok into the book; "Tampico" and "Across the Alley from the Alamo" became the band's biggest sellers, and the theme "Artistry in Rhythm" gave the whole era its name.

In September 1947, after a five-month layoff, Kenton reassembled a larger and deliberately uncommercial band and called what it played Progressive Jazz. Rugolo wrote most of the book; Bob Graettinger contributed "Thermopylae" and the sprawling four-movement "City of Glass," premiered in Chicago in April 1948. Eddie Safranski played bass and Shelly Manne drums, Laurindo Almeida brought classical guitar and Jack Costanzo bongos into a jazz orchestra for the first time in Kenton's band, and Latin material such as Rugolo's "Introduction to a Latin Rhythm" and the band's "The Peanut Vendor" sat alongside Graettinger's atonal writing. The band took five first-place finishes in the Down Beat polls at the end of 1947 and played Carnegie Hall, Symphony Hall in Boston, the Chicago Civic Opera House, and the Hollywood Bowl, where a June 12, 1948, concert drew more than 15,000 people and paid Kenton $13,000. He shut the orchestra down on December 14, 1948, at the Paramount Theatre in New York.

The 1950-51 Innovations in Modern Music orchestra was the largest thing Kenton ever put on the road: thirty-nine musicians including sixteen strings, a woodwind section, and two French horns, with Maynard Ferguson, Shorty Rogers, Art Pepper, Bud Shank, Bob Cooper, Almeida, Manne, and Christy in it. Two tours lost money and Kenton went back to a nineteen-piece band in 1951, this time with a book by Gerry Mulligan, Johnny Richards, Bill Holman, and Bill Russo that pointed toward bebop rather than the concert hall. That band recorded New Concepts of Artistry in Rhythm over September 8-16, 1952, with Lee Konitz on alto, Ferguson and Conte Candoli on trumpets, Frank Rosolino on trombone, Sal Salvador on guitar, and Stan Levey on drums. Mel Lewis took the drum chair in 1954 and stayed through 1956, the period most often described as Kenton's hardest-swinging; the July 1955 Chicago sessions for Contemporary Concepts put Charlie Mariano and Lennie Niehaus in front of Holman's arrangements. Cuban Fire!, Johnny Richards's Afro-Cuban suite recorded May 22-24, 1956, reached No. 17 on the Billboard chart, and the stereo remakes on Kenton in Hi-Fi reached No. 22 the same year. It was on this band that bassist Oscar Pettiford placed the young baritone saxophonist Pepper Adams, who toured with Kenton for most of 1956 in the gig that first put him in front of a national audience.

The other thing 1956 produced was the worst controversy of Kenton's career. Returning from a European tour and finding the Down Beat critics poll dominated by Black musicians, he wired the magazine complaining of "a new minority, white jazz musicians"; Leonard Feather answered with an open letter in the October 3, 1956, issue questioning his racial views. Fewer than two percent of the 600-plus musicians who passed through Kenton's bands over four decades were Black. Musically the late 1950s stayed strong: Standards in Silhouette, recorded September 21-22, 1959, with Bill Mathieu's arrangements and Mariano's alto, is among the most admired of his ballad records. In 1960 he rebuilt the orchestra around a section of mellophoniums, a forward-belled hybrid pitched between trumpet and trombone, and made eleven LPs with it. Kenton's West Side Story, cut March 15-16 and April 11, 1961, at the Goldwyn Sound Stage in Hollywood with Richards arranging, reached No. 16 on the Billboard chart and won the 1962 Grammy for Best Jazz Performance, Large Group; Adventures in Jazz won the same award the following year. The mellophonium band ended with a U.S. and U.K. tour in November 1963, after a divorce decree from the singer Ann Richards required Kenton to spend a year off the road with their two children or lose custody.

Kenton came back in 1965 conducting the Los Angeles Neophonic Orchestra, a concert ensemble whose Capitol album drew a Grammy nomination, but four Capitol LPs between 1966 and 1969, including a 1968 record of music from Hair that he had almost nothing to do with, marked the low point of his recording career and ended his long association with the label and its producer Lee Gillette. In 1970 he founded Creative World Records, bypassed the record business, and sold his own catalog by direct mail to jazz fans. Hank Levy and Bob Curnow wrote for the 1970s bands, which paired veterans with musicians barely out of school: drummer Peter Erskine joined in 1972 for his first professional job and stayed four years, and Tim Hagans, Douglas Purviance, and Mike Vax came through the same way. 7.5 on the Richter Scale (1973), Kenton '76, and Journey into Capricorn (1976) are the best-regarded records of the Creative World period. Kenton had started the Stan Kenton Band Clinics at Indiana University in 1959, the model for most of the summer jazz camps that followed, and he bequeathed his entire orchestra library, more than 2,000 manuscripts by Rugolo, Graettinger, Holman, and Russo, to what is now the University of North Texas, in part so that no ghost band could tour under his name after his death.

Heavy drinking left Kenton accident-prone in his last decade, and a fall in Reading, Pennsylvania, in May 1977 fractured his skull. He gave his last performance on August 20, 1978, was admitted to Midway Hospital near Los Angeles on August 17, 1979, after a stroke, and passed away there on August 25, 1979, at sixty-seven. In 2010 his daughter Leslie Kenton published a memoir, Love Affair, disclosing that her father had sexually abused her between 1952 and 1954, when she was eleven to thirteen; the disclosure later led the University of North Texas to rename a recital hall that had carried his name.

Kenton built his reputation on scale, brass weight, and harmonic ambition rather than on swing, and he was argued about on exactly those grounds for four decades. He enlarged the jazz orchestra past forty players, extended it downward with bass trombones and tubas and upward with high lead trumpet, pushed its dynamic range to extremes, and moved big-band jazz off the dance floor and into the concert hall, which put him at the center of the Third Stream conversation alongside the classical borrowings of Bob Graettinger and Johnny Richards. The trade-off was real: critics who valued rhythmic feel over orchestral color found the 1947-48 and 1950-51 bands cold and overbuilt, and the bands that swing hardest on record are the ones with Mel Lewis in the drum chair and Bill Holman writing. Where he is least disputed is as a talent pipeline. Art Pepper, Stan Getz, Lee Konitz, Maynard Ferguson, Shorty Rogers, Shelly Manne, Bud Shank, Frank Rosolino, Charlie Mariano, Anita O'Day, June Christy, and Peter Erskine all did significant early work in his orchestras, and much of what became West Coast jazz in the 1950s was staffed by Kenton alumni. He entered the Down Beat Hall of Fame in 1954, was voted Playboy's jazz artist of the year in 1957, 1958, and 1959, and the 1943 single of "Artistry in Rhythm" was added to the Library of Congress National Recording Registry in 2011.