Marco Castelli is a saxophonist, composer and bandleader born March 6, 1960, in Venice. He came up through Italian jazz clubs in the 1980s before forming his own working group, the Marco Castelli Quartet, which recorded his debut as a leader, Passat, in 1993 for Splasc(h) Records.

Castelli's early discography runs through Venice's free-improvisation scene around composer Bebo Baldan. He plays soprano and tenor saxophone on four of Baldan's projects: the Effedanza dance company's cassette-only ballet score Music From IAIA (1990, credited to Gottardo Paganin and Baldan), Soniasikri - A Day Of Music (1991, Sub Rosa), Vapor Frames 86/91 (1991, credited to Bebo Baldan Featuring Steve James) and Earthbeat (1995, Materiali Sonori). The same circle produced his most notable outside credit: in March 1993, at Farm Digital Studio in Cessalto, Castelli played soprano saxophone in the roughly two-dozen-piece Venice ensemble Il Suono Improvviso (led by saxophonist Giannantonio De Vincenzo) on Lee Konitz e Il Suono Improvviso a Venezia (Philology), with Lee Konitz appearing as guest soloist on alto and soprano saxophone. Drummer Davide Ragazzoni was also in that ensemble; the two had already crossed paths three years earlier as sidemen on Trieste pianist Roberto Magris's Life in Israel (1990, Jazzis Records, credited to the Roberto Magris Israsextet), and Castelli went on to further Magris sideman dates, including Music Of Today (1990, Roberto Magris & The D.I. Project), Maliblues (1994, Roberto Magris Quartet) and Current Views (2009, Roberto Magris & The Europlane Orchestra) - the last also released under the Europlane Orchestra name, a group with which Castelli separately recorded Live At Zoo Est (1999) and Plays Kurt Weill (2000).

By the 1990s Castelli had also built an electric side of his career fronting DMA Urban Jazz Funk (active 1996-2007), documented on the compilation Dma - Urban Jazz Funk (2000) and Urban Vox (2006, credited to DMA). In 2002 he began conducting the Orchestra della Casa della Musica in Trieste, and in 2004 he founded Bandorkestra.55, an 18-piece big band mixing jazz, Latin and swing repertoire (tracks such as "Quizas Quizas Quizas," "Misirlou," a "Lullaby of Birdland" medley and a "Day Tripper" medley), based at Trieste's Casa della Musica. Bandorkestra.55 recorded Banda Larga (2006), Bandando (2009) and Scorribanda (2012), all for CNI Music, with a compilation of highlights issued as Best Seller (2018).

Castelli returned to smaller-group recording as a leader with Porti di Mare (2014, Caligola), a quartet session with pianist Alfonso Santimone, bassist Edu Hebling, drummer Mauro Beggio and percussionist Andrea Ruggeri drawing on standards by Argentine and Mexican composers alongside his own compositions. He recorded the duo album La bicyclette (2017, Caligola) with vocalist Piera Acone, then formed the Marco Castelli New Organ Trio with organist Matteo Alfonso and drummer Marco Vattovani, releasing Space Age (2021, Caligola). In 2023 he recorded the duo album Songs for a Desert Island with pianist Marco Ponchiroli (Caligola), a collection of jazz standards and film themes. He also guests on saxophone on one track, "The Nearness Of You," of pianist Marcello Tonolo's FinalMente (2018, Arte Sonora), a session built around Tonolo's working trio with bassist Marco Privato and drummer Jimmy Weinstein.

Beyond his own bands, Castelli is a composer for theatre, dance and video, working since 1994 with choreographer Wanda Moretti's Il Posto vertical dance company, which stages performances combining dance, music and architecture on building facades in cities including Singapore, Paris and Bangkok. He is the founder and artistic director of the label Anelli Records and, according to his own biography, has performed in more than 40 countries across the Americas, Africa, the Middle East and Asia, appearing at festivals including the Montreal Jazz Festival, Copenhagen Jazz Festival and the Singapore International Festival of Arts. He is based in Trieste.

Castelli's core identity is a mainstream, post-bop-rooted saxophonist on tenor, soprano and sopranino, but his discography moves across several distinct lanes rather than settling into one: small-group standards and originals (the Marco Castelli Quartet, Porti di Mare, the New Organ Trio), big-band jazz, Latin and swing arranging for Bandorkestra.55, an electric jazz-funk period with DMA Urban Jazz Funk, and a run of early-1990s credits in Venice's free-improvisation scene around composer Bebo Baldan, including a large-ensemble date alongside Lee Konitz. His touring and recording partnerships with Trieste pianist Roberto Magris place him within that city's working jazz scene, distinct from the Bandorkestra big band he leads independently. His parallel career composing for theatre and dance, most durably with Wanda Moretti's vertical dance company, runs alongside rather than inside his jazz output.