McKinley Howard Dorham was born on August 30, 1924, in Fairfield, Texas. He began on piano as a child, learned saxophone and trumpet at L.C. Anderson High School in Austin, and studied chemistry and physics at Wiley College in Marshall, Texas, before entering the U.S. Army. After his discharge he went to Los Angeles to pursue music, worked in a band led by Russell Jacquet, and then moved to New York, where he was soon working in the big bands of the bebop generation.

His early recording credits trace that path. He is on record with Mercer Ellington's orchestra in May 1945, with Billy Eckstine's orchestra on a January 3, 1946 session for National that also included Gene Ammons and Art Blakey, and with Dizzy Gillespie's big band in 1946, including a stand at the Spotlight Lounge in Washington, D.C. and a July 9 session for Musicraft. In August and September 1946 he recorded for Savoy in small groups with Sonny Stitt, Bud Powell, Fats Navarro and Kenny Clarke, the sides later collected under his name as Blues in Bebop. In 1947 he was in Lionel Hampton's orchestra in Los Angeles, and in December of that year he was the trumpeter on a Blue Note date billed to Art Blakey's Messengers, an octet that anticipated the name of the later cooperative.

In late 1948 Dorham replaced Miles Davis in Charlie Parker's quintet. The group, with pianist Al Haig, bassist Tommy Potter and drummer Max Roach, was broadcast from the Royal Roost in New York beginning on December 25, 1948, made studio recordings for Mercury in February, March and May 1949 (among them "Cardboard," "Visa," "Segment" and "Passport"), and played the Paris jazz festival at the Salle Pleyel in May 1949. After leaving Parker he worked as a sideman around New York, played on Thelonious Monk's Blue Note session of May 30, 1952 with Lou Donaldson and Lucky Thompson, and in December 1953 made his first album under his own name, a quintet date for the Debut label, which was run by Charles Mingus and Max Roach, with Jimmy Heath, Walter Bishop Jr., Percy Heath and Kenny Clarke.

In 1954 Dorham, Blakey and pianist Horace Silver formed the cooperative that became the Jazz Messengers. Recording with tenor saxophonist Hank Mobley and bassist Doug Watkins, the band made the Blue Note sessions of November 13, 1954 and February 6, 1955 that appeared as Horace Silver and the Jazz Messengers, and its night at Cafe Bohemia in Greenwich Village on November 23, 1955 produced two live albums. When Blakey took over the Messengers name, Dorham started a band of his own, the Jazz Prophets. Their first album, for ABC-Paramount in April 1956, was followed on May 31, 1956 by a live date at the Cafe Bohemia for Blue Note that added guitarist Kenny Burrell for part of the night and gave pianist Bobby Timmons his recording debut. His own Afro-Cuban (1955), a nonet date with trombonist J.J. Johnson, conguero Carlos "Patato" Valdes and bassist Oscar Pettiford, came from the same period.

After Clifford Brown's death in June 1956, Dorham took his chair in Max Roach's quintet, alongside Sonny Rollins, and stayed until 1958. The group recorded Max Roach + 4 (September 1956) and Jazz in 3/4 Time (March 1957), and Dorham also played on Rollins's Rollins Plays for Bird (October 5, 1956) and on Roach's The Max Roach 4 Plays Charlie Parker and Max! (both 1957-58). Between and after those dates he led a run of Riverside albums: Jazz Contrasts (May 1957, with Rollins, pianist Hank Jones, Pettiford, Roach and the harpist Betty Glamann), 2 Horns/2 Rhythm with the alto saxophonist Ernie Henry (late 1957), This Is the Moment! (1958), on which he sang, and Blue Spring (1959), with Cannonball Adderley. He taught at the Lenox School of Jazz in 1958 and 1959, and recorded in Paris in April 1959 with the saxophonist Barney Wilen, including the soundtrack to the film Un témoin dans la ville. On November 13, 1959 he cut Quiet Kenny with Tommy Flanagan, Paul Chambers and Art Taylor, a ballad-leaning quartet date that includes his tune "Lotus Blossom."

Through 1960 he led quintets for the Jaro and Time labels, several with the baritone saxophonist Charles Davis, then returned to Blue Note for Whistle Stop (January 15, 1961), with Hank Mobley, pianist Kenny Drew, Chambers and drummer Philly Joe Jones, a session often named as his finest. In July 1961 he played the American Jazz Festival in Latin America in Rio de Janeiro, recorded live in San Francisco with Jackie McLean that November (Inta Somethin'), and made Matador for United Artists in April 1962.

In 1963 he added the tenor saxophonist Joe Henderson to his group. The quintet recorded Una Mas for Blue Note on April 1, 1963, with Herbie Hancock, bassist Butch Warren and drummer Tony Williams, and Dorham went on to appear on Henderson's debut Page One (June 3, 1963), which introduced Dorham's composition "Blue Bossa," as well as Our Thing (September 1963) and In 'n Out (April 1964). He also played on Andrew Hill's Point of Departure (March 21, 1964), toured Scandinavia (live albums from Copenhagen's Jazzhus Montmartre in December 1963 were issued later as Scandia Skies and Short Story), and made Trompeta Toccata on September 14, 1964, again with Henderson and Flanagan. In these years he also attended graduate classes in music at New York University and wrote criticism for DownBeat.

His last years were quieter, shaped by kidney disease. He played the Half Note in February 1966, recorded on Cedar Walton's Cedar! (1967), Barry Harris's Bull's Eye! (June 1968), Toshiko Akiyoshi's Toshiko at Top of the Gate (July 1968) and Cecil Payne's Zodiac (December 1968), and led a sextet at the Charlie Parker Memorial Concert in Chicago on August 16, 1970, with pianist Muhal Richard Abrams and the violinist-trumpeter Ray Nance. Dorham passed away in New York City on December 5, 1972, at 48. He was honored at the Longhorn Jazz Festival in Austin in 1966 and as an inaugural inductee of the Austin Music Memorial in 2008; a mural of him was painted in East Austin in 2019, and Jazz at Lincoln Center held a centennial celebration of his birth in 2024. A previously unissued 1967 club recording from the Bronx appeared on Resonance in 2025.

Dorham's tone was clear, sharp and unusually pure, and it was most often praised on ballads, where he played a melody slowly and plainly rather than ornamenting it. Fast or slow he favored long, flowing, singing lines and a precise attack, and he held back from showy displays, which may partly explain why a gifted all-round trumpeter was never as visible as his peers. Britannica names Dizzy Gillespie, Fats Navarro and Miles Davis as his influences, and Charlie Parker's band gave him his bebop grounding. He was also a composer: "Blue Bossa," a hard bop and bossa nova blend sometimes linked to his 1961 visit to Rio de Janeiro, became a jazz standard, his other originals include "Lotus Blossom" (also known as "Asiatic Raes"), "Una Mas" and "Whistle Stop," and Afro-Cuban (1955) was an early hard bop album built around Latin percussion. The writer Gary Giddins observed that Dorham's name had become close to a synonym for "underrated." His Blue Note albums with Joe Henderson, above all Una Mas and Trompeta Toccata, were singled out by AllMusic as a lasting influence on post-bop, and Henderson's own profile describes Dorham as the mentor who opened the door to Blue Note. Trumpeters including Woody Shaw, Duane Eubanks and Itamar Borochov place him in the lineage they come from, Cecil Payne dedicated Zodiac in part to his memory, and his longtime baritone saxophonist Charles Davis recorded a live Tribute to Kenny Dorham in Basel in 2009.