A leader among international opera companies for nine decades, San Francisco Opera was founded by Gaetano Merola (1881–1953) and incorporated in 1923. The Company's first performance took place on September 26, 1923 in the City's Civic Auditorium (La Bohème, with Queena Mario and Giovanni Martinelli, conducted by Merola). Originally presented over two weeks, San Francisco Opera's season now contains approximately 75 performances of ten operas between September and July.

San Francisco Opera inaugurated its current home, the War Memorial Opera House, with a performance of Tosca on October 15, 1932 (Claudia Muzio, Dino Borgioli, and Alfredo Gandolfi sang the principal roles in a production conducted by Merola). The venerable beaux arts building holds the distinction of being the first American opera house that was not built by and for a small group of wealthy patrons; the funding came thanks to a group of private citizens who encouraged thousands of San Franciscans to subscribe.