The Orchestre de la Suisse Romande (OSR) is a Swiss symphony orchestra, based in Geneva at the Victoria Hall. In addition to symphony concerts, the OSR performs as the opera orchestra in productions at the Grand Théâtre de Genève.
Ernest Ansermet founded the OSR in 1918, together with Paul Lachenal, with a contingent of 48 players and a season of six months' duration. Besides Swiss musicians, the OSR players initially came from other countries, including Austria, France, Germany and Italy. Ansermet gradually increased the percentage of Swiss musicians in the orchestra, attaining 80% Swiss personnel by 1946. He remained the music director of the OSR for 49 years, from 1918 to 1967.
A Swiss radio orchestra based in Lausanne was merged into the OSR in 1938. Subsequently, the OSR began to broadcast radio concerts regularly on Swiss radio. The orchestra had a long-standing contract for recordings with Decca Records, dating from the tenure of Ansermet, and made over 300 recordings for Decca, starting in 1947 with Debussy's La mer. The OSR premiered many works of the Swiss composers Arthur Honegger and Frank Martin. During the directorship of Armin Jordan (1985–1997), the OSR continued to make recordings on the Erato label.