Masaru Satō (May 29, 1928 – December 5, 1999) was a Japanese composer of film scores. He was born in Toru City, Hokkaidō and raised in Sapporo. While studying at the National Music Academy, Sato came under the influence of Fumio Hayasaka (早坂文雄), Akira Kurosawa's regular composer for his earlier films. He became a pupil of Hayasaka's, studying film scoring with him at Toho Studios, and working on the orchestration of Seven Samurai (1954). When the older composer died suddenly in 1955, leaving the scores to Kenji Mizoguchi's New Tales of the Taira Clan, and Kurosawa's Record of a Living Being incomplete, Toho assigned Sato to finish them. His first original score was for Godzilla Raids Again in 1955. He wrote the music to all of Kurosawa's movies for the next decade, including Throne of Blood, The Bad Sleep Well, Yojimbo, Sanjuro, and Red Beard. In addition to Mizoguchi and Kurosawa, Satō worked with Hideo Gosha.
His work in the realm of popular film continued throughout his career, composing the scores to Ishiro Honda's The H-Man (1958), The Lost World of Sinbad (1963), and three Jun Fukuda-directed Godzilla films: Godzilla vs. the Sea Monster (1966), Son of Godzilla (1967), and Godzilla vs. Mechagodzilla (1974). During his 44-year association with Toho Studios, he wrote more than 300 film scores.
Satō's style differs considerably from Akira Ifukube (伊福部昭), the principal composer of the Godzilla films. Ifukube's scores show strong roots in European classical music, as well as influences from Japanese traditional and Ainu folk music. Sato, however, employed Western popular styles and light jazz in his film scores. Unlike Ifukube, Sato apparently never felt the need to compose for the concert stage, writing exclusively for film.