Mario Sereni (March 25, 1928 – July 24, 2015) was an Italian baritone, who sang leading roles at the New York Metropolitan Opera for many years. Sereni was born in Perugia, Italy. He attended the Accademia di Santa Cecilia in Rome and the Accademia Chigiana in Siena where he was a pupil of Mario Basiola. His professional career began in 1953, at the Maggio Musicale Fiorentino and within four years he made his debut at the Metropolitan Opera on November 9, 1957, as Gérard in Andrea Chénier. Mario Sereni retired in 1986. He died in Perugia in 2015.