The Stéphane Ratel Organisation (SRO) is a motorsport organization founded by French driver Stéphane Ratel in 1995. Based in London, the company is involved in the promotion, support, and organization of various national and international auto racing series around the world. The group is backed by the Fédération Internationale de l'Automobile (FIA), who provide the regulations for all international and most national SRO series. Local regulatory bodies also assist the SRO, such as the Fédération Française du Sport Automobile (FFSA) and Royal Automobile Club of Belgium (RACB).
Stéphane Ratel founded the Venturi Trophy in 1992, a one-make racing series aimed at wealthy amateurs. After the success of the series, he convinced the Automobile Club de l'Ouest to reintroduce grand tourers at the 1993 24 Hours of Le Mans, which included seven Venturi entries. Later he assisted in the creation of the BPR Global GT Series in 1994. Ratel founded the SRO to expand on his experience with BPR and begin to expand smaller national or one-make series.
The main organisation of the SRO is the Motorsports Group, which acts as organizers for auto racing series. Although the main group works with all series, there are German, Belgium, and Latin American divisions that concentrate on specific series within their region. Most racing series are grand tourer-based, but not all. Most SRO-run national series have adopted the racing formula that the FIA GT3 European Championship laid out in 2006 with its founding by the SRO and FIA.
*Series/events held online in 2020 through Assetto Corsa in the wake of COVID-19