Soyo Oka (岡 素世, born April 9, 1964) is a Japanese composer of video games. Oka began composing at the age of 15 and majored in composition at the Osaka College of Music. She was hired by Nintendo in 1987 and worked there until 1995.
Oka initially wrote mostly for Famicom racing games. In 1990 she and Koji Kondo (whose work she had studied in college) composed the soundtrack to the SNES launch title Pilotwings. Thereafter she worked for higher-profile games, such as SimCity (1991). Oka has composed for four Mario games: Famicom Grand Prix II: 3D Hot Rally, Super Mario Kart, Super Mario All-Stars (where she also arranged Kondo's music), and the NES release of Wario's Woods.
In 1995 she left Nintendo to continue her profession as a freelancer. As of 2017 she is a member of the sound production company At-Tude.
She cites as her musical influences Prokofiev, Rachmaninoff, Chopin, Debussy, Stravinsky, John Williams, Lyle Mays, YMO, Queen, and Chick Corea. Of the pieces she has written, her favorites are Super Mario Kart's Rainbow Road and Princess themes, SimCity's Metropolis theme, and Pilotwings' select theme.