The Gran Turismo World Series (GTWS) is a global sim racing esports tournament series organised by video game developer Polyphony Digital. It consists of two series that are held concurrently throughout the year; the Nations Cup (entrants from their respective countries will represent them) and the Manufacturers Cup (entrants will race for and represent their chosen manufacturer), with players earning points towards qualifying for LAN midseason tournaments known as World Tours, culminating in the annual championship event known as the World Finals. The series uses Polyphony Digital's latest game, Gran Turismo 7.

From 2018 to 2021, the Gran Turismo World Series was previously sanctioned by the Fédération Internationale de l'Automobile. Polyphony Digital's partnership with the FIA was later exclusive to the Olympic Esports Series, which lasted only one year. The series has served as a basis of starting a career in esports before entering real-world motorsport.

Polyphony Digital announced its partnership with governing body Fédération Internationale de l'Automobile in June 2014 to provide a more realistic racing experience in virtual motorsport. It permitted the Japanese game developer to feature content certified by the FIA and launch an online championship in Gran Turismo 6 for the following year in 2015. It would be the earliest example of an official online championship managed by Polyphony Digital and sanctioned by the FIA. The following year in 2016, Polyphony and the FIA announced the formation of the FIA-Certified Gran Turismo Championships (FIA GTC).

The series was established in Gran Turismo Sport shortly after the game's release. Many test seasons ran from 2017 to 2018, and the first official season commenced that year. The first World Tour was also held at Nürburgring, which saw Giorgio Mangano from Italy emerge as the first Nations Cup event winner, and Philippe Nicolay, Matthew Thomas, and Anthony Duval, representing BMW, become the first Manufacturer Series event winners. Brazilian racing driver Igor Fraga became the inaugural Nations Cup champion in 2018, and Kanata Kawakami, Vincent Rigaud, and Tyrell Meadows also became the inaugural Manufacturer Series champions that year. As part of the FIA's involvement as a sanctioning body, the champions were also honoured at the FIA Prize Giving Ceremony.

In 2019, Polyphony Digital and Toyota Gazoo Racing introduced the Toyota GR Supra GT Cup. Originally a one-make series exclusive to the Toyota GR Supra, the series was later expanded in 2021 to include the rest of Toyota's lineup available in the game. The series was later renamed the Toyota Gazoo Racing GT Cup.

The format for the series changed in 2021 in the wake of the COVID-19 pandemic. All previously planned live events were dropped, and the season would instead be held online. Italian player Valerio Gallo won the 2021 World Finals and became the final Gran Turismo Sport champion.

The series transferred over to Gran Turismo 7 for the 2022 season. Polyphony's partnership with the FIA was also put on hiatus that year, with FIA's Director of Innovative Sporting Projects, Frederic Bertrand, stating that they would resume the collaboration once Gran Turismo 7 becomes a sufficiently stable platform. As a result, the FIA name was dropped, and the tournament was renamed to the Gran Turismo World Series (GTWS). Two live events were reintroduced as part of the 2022 season, with the series returning to Hangar-7 in Salzburg, Austria for the Showdown and Monte-Carlo Sporting in Monte Carlo, Monaco for the World Finals.

On April 2025, the Toyota Gazoo Racing GT Cup officially concluded, with a post on X by Toyota confirming its discontinuation.