The Monte-Carlo Philharmonic Orchestra (French: Orchestre Philharmonique de Monte-Carlo) is the main orchestra in the Principality of Monaco. The orchestra gives concerts primarily in the Auditorium Rainier III, but also performs at the Salle des Princes in the Grimaldi Forum.
The orchestra was founded in 1856 and gave its first concert on 14 December 1856, with an ensemble of 15 musicians, at the "Maison de jeux" (the future casino), under the direction of Alexandre Hermann. By 1874, the orchestra had increased in size to 70 musicians, in particular during the leadership of Eusèbe Lucas. In 1953, Prince Rainier III had ordered the renaming of the ensemble to L'Orchestre National de l'Opéra de Monte-Carlo. The orchestra acquired its current name in 1980, again through Rainier III.
Past principal conductors of the orchestra have included Paul Paray, Louis Frémaux, Igor Markevitch, Lovro von Matačić, Lawrence Foster, Gianluigi Gelmetti, James DePreist, Marek Janowski, and Yakov Kreizberg. Kreizberg had originally been signed to a contract of five years, but his tenure was truncated by his death in March 2011. In March 2012, the orchestra and its president, Princess Caroline of Monaco, announced the return of Gelmetti to the orchestra as chef référent to provide interim artistic leadership for the orchestra. In January 2013, the orchestra formalised the full re-appointment of Gelmetti as its artistic director and music director. Gelmetti concluded his second Monte Carlo tenure after the 2015–2016 season and has taken the title of honorary conductor.