Marcello Panni (Rome, January 24, 1940) studied piano, composition and conducting at the Santa Cecilia Conservatory in Rome, his hometown. He went on to specialize in composition at the Santa Cecilia Academy under Goffredo Petrassi, and conducting at the Conservatoire National Supérieur de Musique et de Danse de Paris under Manuel Rosenthal. He made his conducting debut in 1969 at the Venice Biennale, in a concert featuring the music of Goffredo Petrassi. Ever since, Panni’s career has been focused on composing and conducting.

Panni debuted as a composer with works like Prétexte for orchestra (Rome, 1964), Empedokles-Lied (based on 'The Death of Empedocles' by Friedrich Hölderlin) for baritone and orchestra (Venice, 1965), Arpège for harp and percussions (Paris, 1967), D’Ailleurs for string quartet (London, 1967), Patience for choir and orchestra (New York, 1968). In 1971 he founded Ensemble Teatro-Musica. The group toured successfully throughout Europe, performing and recording works by Schnebel, Cage, Pennisi, Berio, Bussotti, Clementi, Donatoni, Feldman; at the Piccola Scala in Milano they performed Klangfarbenspiel, a musical pantomime in collaboration with Piero Dorazio amd Mario Ricci (1972); they performed Savinio’s La Partenza dell’Argonauta at Maggio Musicale Fiorentino, in collaboration with Memè Perlini and Antonello Aglioti (1976). By the late 1970s Marcello Panni was a regular guest featured at Italy’s leading musical institutions and at some of the world’s top opera houses, including the Opéra in Paris, the Metropolitan Opera in New York, the Bolshoi Theater in Moscow, and the Staatsoper in Vienna. He conducted the world premiere of Morton Feldman’s Neither at the Rome Opera House (1976), Silvano Bussotti’s Cristallo di Rocca at La Scala in Milano (1983), and Philip Glass’s The Civil Wars at the Rome Opera House (1984). From 1980 to 1984 Panni taught composition at Mills College in Oakland, California, where he occupied the prestigious Milhaud Chair.

Later compositions by Panni include Trenodia for viola and 11 strings (Rome, 1991), Missa Brevis for choir and children’s voices, wind instruments and percussion (Nice, 2000), Sinfonietta for chamber orchestra (Milano, 2001). Panni has also composed several operas, including Hanjo (1994), based on a modern No by Yukio Mishima, directed by Bob Wilson, and commissioned by Maggio Musicale Fiorentino; Il Giudizio di Paride, libretto by Panni, based on Lucian of Samosata’s 'Dialogues', written for the Bonn Opera (1996); The Banquet (Talking About Love), libretto by Kenneth Koch, commissioned by the Brema Opera (1998), with performances in Rome, Genoa and Florence in 2001 and 2002. In April 2005 at the San Carlo Theater in Naples, Panni presented Garibaldi en Sicile, libretto by Kenneth Koch, based on 'Les Garibaldiens' by Alexandre Dumas, which was commissioned by the famed Neapolitan theater. 

In 1994 Panni was appointed artistic director for the Pomeriggi Musicali Orchestra in Milano, and named musical director of the Bonn Opera. In September 1997 he became musical director of the Nice Opera and Philharmonic Orchestra. From 1999 to 2004 Panni served as artistic director at the Rome Philharmonic Academy. In the fall of 2000, he left the Nice Opera and began a 2-season stint as artistic consultant for the San Carlo Theater in Naples. From 2007 to 2009 Panni was once again artistic director of the Rome Philharmonic Academy.  From 2008 to 2012, Panni was artistic director and principal conductor for the Tito Schipa Symphony Orchestra in Lecce. He has been artistic director for the Sicilian Symphony Orchestra in Palermo since 2018. He became a Fellow at the Santa Cecilia Academy in Rome in 2003.