The National Symphony Orchestra (Spanish: Orquesta Sinfónica Nacional, OSN) is the most important symphony orchestra in Mexico. With its origins traced back as 1881, along with the Boston Symphony Orchestra, it is the second-oldest symphony orchestra in the American continent. The orchestra does not have a permanent venue but performs regularly in the Grand Hall of the Palace of Fine Arts (Palacio de Bellas Artes) in Mexico City.
Not to be confused with the Orquesta Sinfónica del Estado de México (OSEM) or Symphony Orchestra of the State of Mexico, founded in 1971, the National Symphony Orchestra of Mexico, as a branch of the Instituto Nacional de Bellas Artes, was created by presidential decree of Miguel Alemán on 18 July 1947, under the name of National Conservatory Symphony Orchestra.