Marcello Viotti was a major European opera conductor, with notable appearances and an international reputation on the concert stage as well.

Viotti was the son of an Italian family living in Switzerland, leading commentators attributing the fact that his primary activities are in the opera house to his ancestry. His musical training is, however, Swiss. He began studying piano and singing at the conservatory in Lausanne. He took more advanced studies in the same disciplines at the Conservatory of Geneva and added conducting to his interests. In 1984 he won first prize in conducting at the Gino Marinuzzi Competition of San Remo, Italy.

In 1986 he received an appointment as Kappelmeister of the Opera Regio of Turin, Italy, remaining in that post until 1989. Simultaneously, he was artistic director of the Opéra de Lucerne, Switzerland (1987-1991).

In 1990 he became general music director of the City of Bremen (until 1993) and was the chief conductor of the Symphony Orchestra of Saarland Radio in Germany for five years. Also in 1990 he attracted major attention when he took over on short notice conducting the Berlin Philharmonic Orchestra, replacing Riccardo Muti.

From about that time onwards he frequently appeared as a guest conductor in the pits of major European opera houses, such as the Vienna State Opera, the Deutsche Oper Berlin, La Scala of Milan, the Zürich Opera, Opéra-Bastille of Paris, and La Monnaie in Brussels, as well as the Metropolitan Opera in New York. He led his first concert with the Vienna Philharmonic Orchestra in 1997 in an appearance at the Mozart Week of Salzburg. He has also conducted the orchestras of all the German radio organizations, the English Chamber Orchestra, the Bamberg Symphony, the Munich Philharmonic, the Oslo Philharmonic, the Vienna Symphony Orchestra, the Tonhalle Orchestra Zürich, and the Japan Philharmonic.

Viotti has recorded on the Koch-Schwann, Claves, Orfeo, Berlin Classics, and Erato labels. He became one of three principal conductors of the MDR (Middle German Radio) Symphony Orchestra in Leipzig between 1996 and 1999, and in September 1998 was appointed guest conductor of the Japan Philharmonic, as well as taking over the post of chief conductor of the Munich Radio Orchestra.