Chris McCarthy grew up outside Seattle and came to jazz through the music program at Roosevelt High School, one of the strongest scholastic jazz programs in the United States. In 2012, while playing piano in the 2011-2012 Roosevelt Jazz Band, he won the Monterey Jazz Festival's national big band composition competition and its associated Gerald Wilson Award. He left for Boston and the New England Conservatory, graduating with honors in 2016.

The Boston years did as much for him as the conservatory did. Between 2013 and 2016 he worked the city's clubs constantly: Friday and Saturday nights at Wally's Cafe behind trumpeter Jason Palmer and saxophonist Noah Preminger, and Monday nights at the Lily Pad with George Garzone, Jerry Bergonzi, Phil Grenadier, John Lockwood and Bob Gullotti. He held the piano chair in Bergonzi's quintet for two years. When Jeff Ballard, Doug Weiss or Dave Liebman passed through town, McCarthy tended to end up on the gig. His teachers at NEC included the drummer Billy Hart.

His first record came out of that period. Sonder premiered on March 31, 2016 at his senior recital in the Keller Room at NEC, a continuous 45-minute suite for a band of Carrie Furniss (voice), Max Light (guitar), Simon Willson (bass) and Jongkuk Kim (drums). It was recorded a month later at WGBH's Fraser Performance Studio in Boston, live and in a single take with no overdubs, and released in 2017 on Red Piano Records.

McCarthy moved to New York in 2016 and spent the next several years mainly as a sideman: Jason Palmer's two 2018 SteepleChase live albums At Wally's Volume 1 and Volume 2, Jared Sims's The New York Sessions on Ropeadope, vibraphonist Sasha Berliner's Azalea, keyboards on three tracks of trumpeter Takuya Kuroda's Fly Moon Die Soon (2020), and the piano chair on Eden Bareket's Day Dream (2021). He also began a long-running duo with the singer Vanisha Gould, whose first session together took place in September 2016, three weeks after Gould arrived in New York. Alongside the jazz work he tours as pianist with the Mark Morris Dance Group, on productions including Pepperland, The Look of Love and Dances to American Music.

His own leader catalog restarted in 2020 with Still Time To Quit on Ropeadope, cut at The Bunker Studio in Brooklyn on June 12 and 13, 2019 with Kuroda, Michael Blake on tenor and flute, Sam Minaie on bass and Jongkuk Kim on drums. Paul Rauch placed it third in the Seattle Times' best local jazz albums of 2020. The pandemic then stalled him: by his own account in the Priorities liner notes he wrote nothing between March 2020 and March 2021, and the album that broke the block, Priorities (Fresh Sound New Talent, 2023), is a trio record with Chris Tordini and Steven Crammer built from deliberately sparse writing. He credited playing on Bareket's Day Dream with pointing him toward the Barcelona label, which has since released three records involving him.

Life's a Gig (Fresh Sound New Talent, January 2024), the duo album with Gould after seven years of steady work together, drew four and a half stars from DownBeat. Add a Zero followed on May 16, 2025, recorded at The Bunker on July 7, 2024 after a ten-day tour from San Francisco to Vancouver, with a quintet of Kuroda, Bareket, Minaie and Crammer. A fifth leader album, Too Late to Quit, is announced for September 18, 2026 on La Reserve, timed to his tenth year in New York.

McCarthy writes deliberately thin charts. The six originals on Add a Zero are, in his phrase from the liner notes, "one pagers," short forms meant to start an improvisation rather than dictate one, and Priorities was written to leave room for the open-ended playing of Tordini and Crammer rather than to move a band through chord changes. That preference goes back to Sonder, which aimed at directness rather than a display set, and it coexists with a strong funk streak on Still Time To Quit and with a second reputation as an accompanist: the Mark Morris Dance Group and the Gould duo both trade on it, and it is what the New York Times had in mind in crediting his "high skill and sensitivity." Hot House Jazz Magazine called him one of the most impressive and original pianists on the New York scene. His album titles carry a running joke about the economics of the work, from Still Time To Quit through Add a Zero to the forthcoming Too Late to Quit.