Gunhild Carling was born on May 7, 1975, in Gothenburg, Sweden, into a family of musicians. Her father, Hans Carling (1945-2017), played trumpet and piano; her mother, Aina Carling, plays banjo, violin and guitar; and her siblings Gerd, Max and Ulf play piano and trombone, clarinet and saxophone, and drums. The family performed together as the Carling Family, and Gunhild was recording on trombone with them as a child: the LP I Lost My Heart in Dixieland (Phontastic), credited to the Carling Family Hot Five, was recorded on July 17-19, 1984, when she was nine, and a second LP, The Carling Family Hot Six, followed in 1987 from sessions made in the family home in late 1985. English Wikipedia says she grew up in the south of Sweden outside Malmö, and her own site names Stockamöllan as her hometown. She has said she never had a music teacher: she began on drums, then took up the recorder, trombone and trumpet, then tap dancing, harmonica and bagpipes, and later began composing. She is listed as the 1985 winner of a Louis Armstrong scholarship. In 1986 she played trombone on six tracks of Bent Persson's Louis Armstrong's 50 Hot Choruses for Cornet as Recreated by Bent Persson, Volume 3 (Kenneth Records, 1987), and the Carling family band also appears on Povel Ramel's nine-LP box Ramels Delikatesser (1986), issued alongside the TV series Affären Ramel.

Her own bands took shape in the 2000s. That's My Desire (Heptown, 2002) was recorded live on February 25, 2002, at the John Bull Pub in Lund by Gunhild Carling and Her Swing Band, with Ola Åkerman on trombone, Olle Larsson on piano, Ludwig Wennström on bass, Rasmus Kihlberg on drums and her brother Max on clarinet and violin; Discogs credits her with trumpet, trombone, harmonica and vocals. Red Hot Jam (Music Mecca, 2004) paired her with pianist Jan Lundgren, bassist Jesper Lundgaard and drummer Rasmus Kihlberg. In 2003 she took trumpet, trombone, harmonica and vocal parts on three tracks of a Music Mecca CD by Papa Bue's Viking Jazz Band with Swedish guests, and Magic Swing! (Heptown, 2007) presented her Carling Big Band in concert at Berwaldhallen in Stockholm on January 25 and February 28, 2006. She won the Kobe Jazz Street Award in 2006, a SKAP scholarship and the Anita O'Day Award in 2009, and, according to her own site, organized the Stockamöllan Swing and Jazz festival from 2006 to 2016 and a yearly January-February tour of Sweden with her big band, a string section and dancers from 2008 to 2016.

Swedish television made her a household name in 2010. After a July 20, 2010, appearance on SVT's Allsång på Skansen she became, with Thomas Deutgen, the commentator pair on Dansbandskampen, and she was also in the Diggiloo show that year. Her solo Christmas album Jul Därhemma (Heptown, 2011) credits her on vocals, trumpet, trombone, bagpipes, harmonica, recorder, accordion, harp, glockenspiel and oboe, and she recorded the duet single "Baby It's Cold Outside" that November with Christer Sjögren and Pernilla Wahlgren. In 2013 her Carling Big Band played at the Royal Palace in Stockholm for King Carl XVI Gustaf's ruby jubilee, and in 2016 she performed at his 70th birthday celebration. The big band's CDs on the family's Carling Records label were Variete (recorded October 2012 in Stockamöllan, with some tracks live in January 2013 at Gothenburg Concert Hall), Swing Out! (December 5, 2013), Harlem Joy (2014) and Big Apple (June 26, 2015). In 2014 she finished third as a celebrity dancer in TV4's Let's Dance and was named Scanian of the Year, and in 2016 she received the Thore Ehrling scholarship and spoke at TEDxArendal.

From about 2017 she became widely known abroad through Scott Bradlee's Postmodern Jukebox, appearing in vintage-jazz video arrangements of pop songs, among them "Never Gonna Give You Up," "Material Girl," "The Final Countdown," "Happy" (on which she plays ten instruments) and "Dancing Queen"; several of her videos have passed a million views. Discogs credits her as a featured performer on the group's 33 Resolutions Per Minute (January 2017), Blue Mirror (September 2018) and The Essentials II (November 2018). She moved with her family to northern California in 2018, and her site dates her U.S. touring with the group from 2018 to 2022. She also plays trumpet on one track of the vinyl edition of Sabrina Carpenter's Singular Act II (2019).

Since 2022 she has led her own American-based projects. Good Evening Cats! was recorded in New York in February 2022 with pianist Billy Stritch, bassist Steve Doyle, drummer Daniel Glass and saxophonist Jason Bellenkes, among others, with her husband, Johan Blomé (they married in 2003), and her children Viggo and Idun also taking part. She headlined a run at Birdland in New York in February 2023 billed as Gunhild Carling, Family and Friends, issued the vinyl LP Live at Müpa Budapest with the BJC Big Band (recorded in 2019), and released Happy Christmas and a new Carling Family album in 2023. In 2024 she gave a TEDxPaloAlto talk on the history of the jazz trumpet and released Jazz Is My Lifestyle, a big band album with the Prague Strings Chamber Orchestra and trumpeter Scotty Barnhart as a guest. On February 12, 2025, she recorded the live EP Live on Bourbon Street with Kevin Ray Clark and Fritzel's All Star Band at Fritzel's Jazz Club in New Orleans, and in November 2025 she appeared as a guest with the Count Basie Orchestra under Barnhart's direction on opening night of its European tour at Ronnie Scott's Club in London, where a reviewer noted her recorder, trumpet, trombone and bagpipes. As of November 2026 she continues to tour in the United States.

Carling works in the hot, small-band and big-band idioms of the 1920s to 1940s, and she names early New Orleans-era players as her models, among them Louis Armstrong, Freddie Keppard, Jelly Roll Morton and Bix Beiderbecke. English Wikipedia also hears the influence of Billie Holiday in her singing, and a 2024 album reviewer heard an Armstrong-like trumpet solo on her song "Winter's Day." Her signature is range: a single number may move from trumpet to trombone, recorder, harp, bagpipes or harmonica, with tap dancing and vocals in between, and she describes herself as Sweden's queen of swing, jazz and vaudeville. Her Carling Big Band includes family members who double on several instruments, and the family band keeps the early-jazz repertory of Dixieland and swing at the center. That entertainer's side, along with her work for Postmodern Jukebox and on television, has made her more visible than most traditional-jazz players of her generation, and a London reviewer in 2025 singled out her trombone as the serious playing underneath the comedy.