Gran Turismo is the highest-selling video game franchise under the PlayStation brand.
Developed by Polyphony Digital and published by Sony Interactive Entertainment, Gran Turismo has been tied to PlayStation hardware since the original game debuted in Japan in 1997. The series has sold more than 100 million copies worldwide, making it one of Sony’s most commercially successful gaming properties and the leading franchise associated with the PlayStation brand.
Its success began with the first Gran Turismo, which became the best-selling game on the original PlayStation. Later entries also performed strongly: Gran Turismo 3: A-Spec became one of the PlayStation 2’s biggest sellers, while Gran Turismo Sport sold nearly 13 million copies. The wording can cause confusion because the franchise is a racing series rather than a console itself. The question asks for the console brand associated with the series, not the publisher or developer, so PlayStation is the canonical answer.