Benny Benack III was born on November 23, 1990 in Pittsburgh, into the third generation of a family that had been part of the city's jazz life since the 1940s. His grandfather, Ben E. "Benny" Benack (1921 to 1986), was a trumpeter and bandleader born in Clairton, Pennsylvania to Italian immigrant parents, who studied at Carnegie Institute of Technology, toured with the Tommy Dorsey and Raymond Scott orchestras, ran a working Pittsburgh big band and wrote the Pittsburgh Pirates fight song "Beat 'Em Bucs." His father, Benny Benack Jr., is a clarinettist and tenor saxophonist who spent a career on the region's wedding and function circuit. His mother, Claudia Benack, teaches music theater at Carnegie Mellon University. Benack has credited each side of that inheritance with a different part of what he does: his father's function gigs taught him how to hold a room, and his mother's world gave him the theatrical instinct that sits behind his singing.

He started on piano at five and was handed a trumpet at nine. Growing up in Pittsburgh meant growing up inside a hard bop lineage rather than reading about one. The city produced Art Blakey, Stanley Turrentine, Roy Eldridge and Ahmad Jamal, and its jam sessions enforced a standard Benack has described bluntly: take care of the music, or you find out quickly. Unlike most young trumpeters he did not arrive through Miles Davis. He came in through the hard boppers, Freddie Hubbard and Lee Morgan first, and only later, at the prompting of the Pittsburgh trumpeter Sean Jones, worked back into Davis's Second Quintet and the compositional world of Wayne Shorter. He attended Upper St. Clair High School and was selected for the Gibson/Baldwin Grammy Jazz Ensemble, where his cohort included the pianist Emmet Cohen, the drummer Bryan Carter, the saxophonist Grace Kelly and the tenor player Chad Lefkowitz-Brown, all of whom he still works with.

The competition record from his student years is unusually thick for a player who is now better known for singing. He won the Carmine Caruso International Jazz Trumpet Solo Competition and the International Trumpet Guild jazz competition in 2011 and the National Trumpet Competition in 2012, reached the finals of the Gentlemen Sing vocal competition in 2013, and in 2014 was named one of thirteen semifinalists in the Thelonious Monk Institute International Jazz Trumpet Competition, a field that also included Marquis Hill, Adam O'Farrill, Philip Dizack and Hermon Mehari. He took a full-tuition scholarship to the Manhattan School of Music, finishing a Bachelor of Music in 2013 and a Master of Music in 2015, and stayed in New York.

Two working bands carried him through the middle of the decade. In 2013 the drummer Ulysses Owens Jr. and the pianist Takeshi Ohbayashi formed the New Century Jazz Quintet, an all-acoustic group deliberately built on the instrumentation of Blakey's Jazz Messengers, and Benack took the trumpet chair. The quintet recorded four albums for the Japanese label Spice of Life between 2014 and 2017 and won the inaugural DCJazzPrix band competition at the DC Jazz Festival in 2016. At the same time he joined Charlie Rosen's 8-Bit Big Band, an ensemble that arranges video-game music for a full jazz orchestra, appearing on its first album in 2017 and on two more in 2021 and 2023. That band won a Grammy for Best Arrangement, Instrumental or A Cappella in 2022, an award that went to its arrangers Rosen and Jake Silverman for a track Benack does not appear on. A third strand of work, the wide pop and crossover side that his publicity leans on, put him on stages with Josh Groban, Ben Folds, Postmodern Jukebox and the designer Isaac Mizrahi, and in Europe with the bassist Christian McBride.

His own catalogue began in 2017 with One Of A Kind, a sextet date cut with a band of contemporaries: Joel Frahm on saxophone, Emmet Cohen on piano, Yotam Silberstein on guitar, Alexander Claffy on bass and Owens on drums, with seven Benack originals among the twelve tracks. A Lot Of Livin' To Do followed in January 2020 with McBride on bass, Ohbayashi on piano and Owens producing, a program that reached from Gigi Gryce and Ray Brown to two Fred Rogers songs, a nod to the Pittsburgh television neighbourhood he grew up watching. In December 2019 he and the arranger Steven Feifke put out a five-track holiday EP, Season's Swingin' Greetings, which they expanded in 2021 into a ten-track big-band album for Cellar Music carrying both Christmas and Hanukkah material.

Third Time's The Charm, released June 30, 2023 on La Reserve and Bandstand Presents, is the record that moved him from a working sideman to a name. It is built on what was then the Emmet Cohen Trio, with Cohen on piano, Russell Hall on bass and Kyle Poole on drums, plus Ruben Fox on tenor, and it brings in Peter Bernstein on three tracks, Chad Lefkowitz-Brown on two, Michael Stephenson on two and the trumpeter and singer Bria Skonberg for a duet on Duke Ellington's "In A Mellow Tone." It reached No. 2 on the JazzWeek radio chart. Since then he has led a project devoted entirely to the unrecorded 1950s and 1960s compositions of the pianist Johnny Anz, released in 2024 as Someday, Somewhere...; recorded a live album at the Blue Llama Jazz Club in Ann Arbor over Labor Day weekend 2024 with his father guesting on tenor, issued in June 2025 as This Is The Life and expanded that September as This Is The (Night) Life; and co-led Roadmap, an all-originals quintet date with the Danish saxophonist Andreas Toftemark cut in February 2025 and released on April Records that November. He holds a residency at Smalls in New York, the club run by Spike Wilner, and appears regularly at Dizzy's Club at Jazz at Lincoln Center, where he also works as a clinician for the organisation's education programs.

Benack is one of the few players of his generation who is genuinely two things at once rather than a trumpeter who also sings a chorus. On the horn he works out of the Hubbard and Morgan hard bop line, with a bright, front-footed attack and a taste for tempo; as a singer he is a straight post-Sinatra crooner with clean intonation, and he is fluent enough in vocalese to sing written lyrics over recorded solos. The New York Times has called him a charismatic young trumpeter who keeps an earnest sideline as a singer, and reviewers reaching for a comparison tend to land on either Chet Baker, for the vulnerable ballad singing, or Louis Prima, for the showmanship; Jazz Weekly's George W. Harris summed the combination up as the heart of a rat packer and the style of a Jazz Messenger. The critics have been willing to reward both halves: the 2023 DownBeat Critics Poll placed him second among Rising Star Male Vocalists while also listing him as a Rising Star Trumpeter, a double placing few musicians manage. His formal recognition as a singer arrived later than as a player, with third place in the 2021 Sarah Vaughan International Jazz Vocal Competition coming a decade after his trumpet competition wins. Publicity from his management and from venues including Smalls and the Pittsburgh Symphony bills him as Emmy-nominated; none of them names the nomination, and it could not be traced to a specific program or category for this profile.