Gerry Hemingway was born on March 23, 1955 in New Haven, Connecticut, into a family with musical interests: his grandmother had been a concert pianist and his father studied composition with Paul Hindemith. He became interested in drums at around ten, attended the Foote School in New Haven, studied with the Boston drummer Alan Dawson, and by seventeen was supporting himself as a working musician, playing mostly in the jazz and bebop traditions. He began performing as a solo percussionist in 1974, at nineteen, and has kept that strand of work running for five decades alongside everything else.

New Haven in the 1970s held an unusual concentration of musicians, and it was there that Hemingway first met and played with pianist Anthony Davis, trumpeter Wadada Leo Smith, trombonist George Lewis and Anthony Braxton. His first record as a leader, Kwambe, came out of that circle: it was cut at Generation Sound Studios in New York on January 10, 1978 and at Right Track Studios on February 20, 1978, and issued as the first release on his own Auricle Records, with Davis on piano, Lewis and Ray Anderson on trombones, Jay Hoggard on vibraphone and Tanzanian xylophone, Wes Brown on Ghanaian flute and bass, and Mark Helias on bass. In the late 1970s Hemingway, Anderson and Helias formed a collective trio they eventually named BassDrumBone. Its first album, Oahspe, was recorded at the Educational Center for the Arts in New Haven on November 22 and 25, 1978 and released on Auricle in 1979. The trio has now been working, on and off, for close to half a century, which makes it one of the longest continuously documented groups in the music.

In 1983 Hemingway joined Anthony Braxton's quartet and stayed for eleven years, until 1994. The first document is Four Compositions (Quartet) 1983, cut at the Barigozzi Studio in Milan on March 9 and 10, 1983 with John Lindberg on bass and George Lewis on trombone. Marilyn Crispell replaced Lewis for Six Compositions (Quartet) 1984, recorded at Vanguard Studios in New York that September, and Mark Dresser took over the bass chair for Five Compositions (Quartet) 1986. The Braxton, Crispell, Dresser, Hemingway lineup that resulted stayed together for the better part of a decade and is generally held to be the most fully realised of Braxton's working quartets, documented on Quartet (London) 1985, Willisau (Quartet) 1991, (Victoriaville) 1992, Twelve Compositions from Yoshi's in Oakland in July 1993, and Quartet (Santa Cruz) 1993, among many others. In August 2007 Hemingway and Braxton reconvened as a duo in the Daltry Room at Wesleyan University and taped the four discs released as Old Dogs (2007).

Two other long American associations ran through the same period. From the late 1980s Hemingway played in the Reggie Workman Ensemble, a group whose personnel at various times included Oliver Lake, Jeanne Lee, Marilyn Crispell, John Purcell and Don Byron; the records are Images, taped at the Knitting Factory in 1989, Altered Spaces, from Swarthmore College in February 1992, and Workman's Cerebral Caverns of 1995. He was also a core member of Anthony Davis's Episteme Ensemble and appeared as a featured soloist in Davis's violin concerto Maps and in the operas Under the Double Moon and Tania, as well as playing percussion on the 1989 recording of Davis's X, The Life and Times of Malcolm X. In May 1999, at the invitation of the Antwerp venue De Singel, he performed a duet with Cecil Taylor.

His own bands have taken two main shapes. The quintet began in 1985 with Outerbridge Crossing, recorded at Presence Studio in New Haven that September with David Mott on baritone saxophone, Ernst Reijseger on cello, Ray Anderson on trombone and tuba and Mark Helias on bass. By 1990 the group had turned European and was carrying a very unusual front line: cello, trombone and reeds with no chordal instrument at all. Special Detail, taped live in Bielefeld in October 1990, has Ed Schuller on bass, Reijseger on cello, Don Byron on clarinet and baritone saxophone and Wolter Wierbos on trombone. From Demon Chaser (Wuppertal, March 1993) onward the band settled into Michael Moore on alto saxophone and clarinets, Mark Dresser on bass, Reijseger on cello and Wierbos on trombone, and in that form it made Slamadam, The Marmalade King, Perfect World and Waltzes, Two-Steps & Other Matters of the Heart, the last drawn from the Berlin Jazz Festival and a Stockholm club date in November 1996. A later quintet, formed in 2008 with Ellery Eskelin, Oscar Noriega, Terrence McManus and Kermit Driscoll, produced Riptide in 2011 and toured Europe in 2012.

The quartet ran alongside it. Down to the Wire, recorded in Utrecht and Bremen in December 1991, is the quintet band minus the cello. From 1997 to 2007 Hemingway's primary working group was a different quartet with Ellery Eskelin on tenor saxophone, Mark Dresser or Mark Helias on bass, and a brass chair filled by Ray Anderson or Herb Robertson; it played forty American concerts in 1998 and recorded Devil's Paradise (1999) and The Whimbler (2004). Its first album, Johnny's Corner Song, taped live at the Grand Theatre in Groningen on November 14, 1997, has Robin Eubanks rather than Anderson or Robertson in the trombone chair.

Hemingway has written for ensembles well outside jazz instrumentation. In 1993 he premiered Terrains, a concerto for percussionist and orchestra commissioned by the Kansas City Symphony with Meet the Composer funding. Four commissions came through the Parabola Arts Foundation with New York State Council on the Arts money, including the 1998 grant behind The Visiting Tank, which closes his 1999 Tzadik album Chamber Works, a programme of string quartet and mixed chamber pieces recorded at Merkin Hall in New York and released under John Zorn's executive production. In June 1998 the Dutch broadcaster NPS commissioned Cycles, a co-composition with the Amsterdam composer Guus Janssen performed at the Holland Festival using a computer-controlled conducting system that let the ensemble play in several tempos at once. He received fellowships from the National Endowment for the Arts and the New York Foundation for the Arts, and in 2000 a Guggenheim Fellowship in music composition.

The solo percussion work is a body of its own, running from the 1981 LP Solo Works through Tubworks (1988) to the pair of Random Acoustics retrospectives issued in 1996, Acoustic Solo Works 1983-94 and Electro-Acoustic Solo Works 1984-95. It arrived at kernelings in 2014, a CD and DVD set fifteen years in the making that set his solo improvising against his own film work, and it fed a staged solo programme, Behaviors, built with the video artist Beth Warshafsky, a collaborator since the late 1980s.

Since 2019 Hemingway has turned toward songwriting and song production. That work produced Afterlife in 2022, recorded and produced entirely by him between 2020 and 2022 and described on his own site as the most significant release of his career, followed by the 2023 single Time Falls Right, on which he sings and plays acoustic guitar rather than drums.

He taught in the New School's Jazz and Contemporary Music programme from 2005 to 2009, running the Sound in Time ensemble and teaching courses in world music history and in contemporary jazz. In autumn 2009 he joined the faculty of the Hochschule Luzern in Switzerland, where he still lives, teaching drumming, improvisation, composition, songwriting and history until his retirement from the post in 2022. His own site counts more than 180 recordings; Discogs credits him on 313 releases under his personal artist entry alone, before his group entities are added.

Hemingway's drumming is built for music with no fixed chord instrument and often no fixed metre, and the sound of his kit reflects that: he has spent a career adding pitched and unpitched material to it, so that vibraphone, marimba, steel drums, harmonica, voice, wood blocks and triggered samplers all turn up under his own name on Discogs credit blocks as part of a single instrument rather than as doubling. On Braxton's Old Dogs (2007) the credit runs to nine separate instruments for one player. His technical foundation is orthodox, learned in New Haven and through study with Alan Dawson, and he was working bebop gigs at seventeen; what he did with it was to treat the drum set as a compositional instrument, which is why the solo records are not filler between band dates but the spine of the catalogue. The three quintet and quartet books of the 1990s are the clearest statement of his writing: cello, trombone and reeds with no piano and no guitar, which throws the harmonic weight onto lines and timbre. He works easily on both sides of the composed and free divide, from through-written string quartet pieces on Chamber Works to wholly improvised duo meetings with saxophonist John Butcher or the analogue synthesist Thomas Lehn, and he has kept up an unusual number of very long partnerships: BassDrumBone since the late 1970s, Georg Gräwe and Ernst Reijseger since 1989, Marilyn Crispell since 1984, the WHO Trio since 1998. Reviewers and programmers have treated him as a first-call improviser on both sides of the Atlantic, and his sideman list runs from Anthony Braxton and Reggie Workman through Kenny Wheeler, Derek Bailey and Oliver Lake to a rock album, John Cale and Bob Neuwirth's Last Day on Earth.