Donald Paul McCaslin was born August 11, 1966, in Santa Clara, California, into a musical household — his father, Don McCaslin, was a working vibraphonist and bandleader, and by age twelve Donny was already performing in his father's ensemble. In high school he led his own group through three consecutive appearances at the Monterey Jazz Festival, and in 1984 he entered Berklee College of Music on a full scholarship. Three years later, in 1987, vibraphonist Gary Burton hired him straight out of Berklee; McCaslin toured internationally with Burton's group for four years, an apprenticeship that took him around the world before he'd turned twenty-five.

In 1991 McCaslin relocated to New York and joined the jazz-fusion group Steps Ahead, planting him inside the city's working scene. The sideman work that followed over the next two decades reads like a survey of the era's most demanding bandleaders: the Gil Evans Orchestra, whose own career is covered in full in his JazzProfiles.com profile; pianist Danilo Pérez, profiled separately on JazzProfiles.com; trumpeter Dave Douglas, profiled separately on JazzProfiles.com — McCaslin is the tenor saxophonist on Douglas's Meaning and Mystery (2006, Greenleaf Music), a credit that later grew into a home-label relationship of its own; and Maria Schneider's Jazz Orchestra, where McCaslin became a recurring featured soloist and, eventually, a three-time Grammy nominee entirely through her book — first in 2004 for Best Jazz Instrumental Solo on "Bulería, Soleá y Rumba" (from Concert in the Garden, which itself won Best Large Jazz Ensemble Album in 2005), and again in 2016 for Best Improvised Jazz Solo on "Arbiters of Evolution" (from The Thompson Fields). A third nomination, also for Best Improvised Jazz Solo, came in 2013 for "Stadium Jazz," off his own Casting for Gravity.

McCaslin built a parallel career as a leader across this same span, debuting in 1998 with Exile and Discovery (Naxos Jazz), a straight-ahead quartet date with pianist Bruce Barth, bassist Ugonna Okegwo, and drummer Billy Drummond. Seen From Above (2000) and The Way Through (2003), both on Arabesque Jazz, began a long-running partnership with alto saxophonist and producer David Binney, who would shape nearly every McCaslin record for the next decade. Soar and Give and Go followed in the same year, 2006, on Sunnyside and Criss Cross Jazz respectively, and Declaration (2009, Sunnyside) expanded to a larger ensemble with guitarist Ben Monder, bassist Scott Colley, drummer Antonio Sánchez, and a small horn section. In 2008, Dave Douglas's artist-run Greenleaf Music released McCaslin's trio record Recommended Tools, beginning a label relationship that would carry his most consequential records.

Perpetual Motion (2010, Greenleaf) marked a turning point: alongside longtime collaborators Binney and Sánchez, it brought drummer Mark Guiliana and bassist Tim Lefebvre into McCaslin's music for the first time. Casting for Gravity (2012) crystallized that shift, pairing Guiliana and Lefebvre with keyboardist Jason Lindner to form the quartet that would define the rest of McCaslin's career — a sound built on angular post-bop lines pushed through dub rhythms, electronica textures, and arena-rock power. The album earned McCaslin his second Grammy nomination and became, by his own account and multiple critics', his tenth and most fully realized leader statement. Fast Future (2015) continued with the same personnel.

That was the band David Bowie found. Producer Tony Visconti had taken Bowie to see Maria Schneider's orchestra at Birdland in May 2014 — McCaslin was in that orchestra — and Bowie decided on the spot to write with Schneider; the song that resulted, "Sue (Or in a Season of Crime)," was recorded that July with McCaslin among the soloists. When Bowie went looking for a smaller band for his next full album, Schneider pointed him toward McCaslin's own working quartet. One Sunday night that same spring, Bowie slipped anonymously into the 55 Bar in Greenwich Village, took a table near the stage, watched a set, and left without introducing himself — McCaslin noticed him only out of the corner of his eye. Days later, an email arrived asking McCaslin to join Bowie's new record. McCaslin brought his own band intact — Lindner, Lefebvre, and Guiliana — and that quartet, with guitarist Ben Monder added, became the core band on Blackstar, recorded across three weeklong sessions at New York's Magic Shop between January and May 2015. The album was released January 8, 2016, Bowie's 69th birthday; he died two days later.

McCaslin's own Beyond Now (2016, Motéma), recorded with the same Blackstar-era quartet, is dedicated to Bowie — two Bowie covers sit alongside reworked Deadmau5, MUTEMATH, and Chainsmokers tracks and McCaslin originals. Blow (2018) pushed further into vocal-driven art rock, with former Bowie bassist and backing vocalist Gail Ann Dorsey among its guest singers. More recently, McCaslin moved to the UK label Edition Records for I Want More (2023), which added a string quartet to his longtime rhythm section, and Lullaby for the Lost (2025), a guitar-driven meld of art rock and modern electric jazz produced with Tim Lefebvre and Jason Lindner and mixed by Dave Fridmann. He teaches at Manhattan School of Music alongside his recording and touring schedule.

McCaslin's tenor voice is rooted in the post-bop and modern-mainstream vocabulary he absorbed under Gary Burton and across two decades of high-level sideman work, but his defining trait as a leader has been a steady, decade-long migration toward electronic and rock textures — a direction already well underway on Casting for Gravity (2012), years before Bowie ever walked into the 55 Bar. His long partnership with producer David Binney shaped the first half of that arc; his working quartet with Jason Lindner, Tim Lefebvre, and Mark Guiliana, formed on Perpetual Motion and locked in by Casting for Gravity, shaped the second, and became — largely intact — the band on Bowie's Blackstar. That sequence makes McCaslin one of the most significant crossover figures bridging jazz and art rock: not a jazz musician recruited into a rock project, but a bandleader whose own fusion of dub, electronica, and arena-scale dynamics had already arrived at that intersection on his own terms.