Edward Lee Morgan was born July 10, 1938 in Philadelphia, the youngest of four children of Otto Ricardo and Nettie Beatrice Morgan. He was drawn first to the vibraphone, but his sister Ernestine gave him a trumpet for his thirteenth birthday and that settled it. He attended the Jules Mastbaum vocational school, led a bebop group at Philadelphia's Music City club, and by fifteen was working weekends professionally in a band co-led with bassist Spanky DeBrest. His decisive influence was fellow Philadelphian Clifford Brown, who gave him lessons and let him sit in. Brown was killed in a car crash on June 26, 1956, weeks after Morgan finished school, and a good part of the jazz press spent the next decade describing Morgan as the player most likely to carry Brown's line forward.

He did not wait long. In November 1956, at eighteen, he cut two leader albums inside a month: Introducing Lee Morgan for Savoy and Lee Morgan Indeed! for Blue Note (recorded November 4, 1956, with Horace Silver, Wilbur Ware and Philly Joe Jones). That same year he joined Dizzy Gillespie's big band, staying roughly eighteen months until economic pressure forced Gillespie to fold the orchestra in 1958. Blue Note kept him working at a startling clip through those months: Lee Morgan Vol. 3 (March 24, 1957), City Lights (August 25, 1957), The Cooker (September 29, 1957, with Pepper Adams on baritone) and Candy. On September 15, 1957 he took the trumpet chair on John Coltrane's Blue Train, playing an instrument with an upswept bell that Gillespie had given him.

When Gillespie's band broke up, Morgan went straight into Art Blakey's Jazz Messengers, the finishing school for a generation of hard bop players. He is on Moanin' (1958), the album that made that edition of the band famous, and when Benny Golson left it was Morgan who talked Blakey into hiring Wayne Shorter. The Morgan/Shorter/Bobby Timmons/Jymie Merritt Messengers recorded The Big Beat (1960), A Night in Tunisia (1960) and The Freedom Rider (1960-1961), and Morgan contributed originals including "The Midget," "Haina," "Kozo's Waltz" and "Blue Lace." He also kept a leader career running alongside it, cutting Here's Lee Morgan and Expoobident for Vee-Jay in 1960 with Blakey on drums. Heroin, which by his biographer Tom Perchard's account Blakey introduced him to, ended the run: Morgan left the Messengers in 1961 and went home to Philadelphia, where he worked only sporadically for close to two years.

He came back to New York in 1963 and on December 21 recorded The Sidewinder at Rudy Van Gelder's studio in Englewood Cliffs, with Joe Henderson, Barry Harris, Bob Cranshaw and Billy Higgins. Released in July 1964, it became the best-selling record Blue Note had ever had, climbing to No. 25 on the Billboard album chart by January 1965 while the title track reached No. 81 on the Hot 100, and it stabilized a label that had been close to insolvent. Drummer Billy Hart has said Morgan cut the tune as album filler and never understood the reaction; Morgan himself thought his playing had advanced further on Grachan Moncur III's Evolution, recorded a month earlier on November 21, 1963. The tune was picked up as the music for a Chrysler television spot that ran during the World Series without his permission, and he threatened legal action until Chrysler pulled the ad and settled. Blue Note then spent years asking its roster for more of the same boogaloo feel, and Morgan supplied some of it himself with "Cornbread" and "Yes I Can, No You Can't." He also filled the trumpet chair with the Messengers again in the mid-1960s after Freddie Hubbard left, appearing with John Gilmore, John Hicks and Victor Sproles in a lineup filmed for the BBC series Jazz 625. Between 1964 and 1968 he recorded roughly twenty more leader dates, several of which Blue Note shelved and did not issue until the late 1970s and 1980s.

The band he led at the end was his most personal: Bennie Maupin or Billy Harper on reeds, Harold Mabern on piano, Jymie Merritt on bass, Mickey Roker or Freddie Waits on drums. It is the group heard on Live at the Lighthouse, taped July 10 to 12, 1970 at the Lighthouse Café in Hermosa Beach during an engagement that opened on his 32nd birthday, and the only live album issued in his lifetime. In those last two years he also became an organizer, helping lead the Jazz and People's Movement, which disrupted the taping of network talk and variety shows through 1970 and 1971 to protest the near-total absence of jazz musicians from their guest slots and house bands. His final studio session, on September 17 and 18, 1971, was released in 1972 as Lee Morgan, commonly called The Last Session. Early on February 19, 1972, during a break between sets at Slugs' Saloon in the East Village, Morgan was shot by his common-law wife, Helen Moore, following an argument. The wound was not immediately fatal, but heavy snow across the city delayed the ambulance badly and he bled to death before reaching hospital. He was 33. Moore served a short prison term, was paroled, and returned to North Carolina, where she died of a heart condition in March 1996. The 2016 documentary I Called Him Morgan, directed by Kasper Collin, tells both their stories.

Morgan built directly on Clifford Brown's foundation, the same rounded, unforced tone and the same command at fast tempos, but he added a needling, vocal quality that Brown never used: half-valve smears, bent notes, sudden squeezed high notes, phrases that stop a beat early and dare the rhythm section to fill the hole. Where Miles Davis pared away and Freddie Hubbard went for brilliance and volume, Morgan played with an almost conversational wit, and he was among the very few trumpeters of the period whose sound is identifiable within two bars. He was also a real composer: "Ceora," "Search for the New Land," "The Sidewinder" and "Totem Pole" all entered the repertoire. Critics have generally split his catalog into the crowd-pleasing boogaloo dates that followed The Sidewinder and the more exploratory sessions, several unissued in his lifetime, on which he worked with modal and free-leaning material; Search for the New Land and the 1967 sextet half of The Procrastinator are the usual evidence for the second category. He is treated today as one of the two or three musicians most central to Blue Note's identity, and The Sidewinder was added to the Library of Congress National Recording Registry in 2024.