The Porsche 911 GT3 is a high-performance homologation model of the Porsche 911 sports car. It is a line of high-performance models, which began with the 1973 911 Carrera RS. The GT3 has had a successful racing career in the one-make national and regional Porsche Carrera Cup and GT3 Cup Challenge series, as well as the international Porsche Supercup supporting the FIA F1 World Championship.

In motorsport, homologation is a testing and certification process for vehicles, circuits, and related equipment for conformance to technical standards, usually known as type approval in English-language jurisdictions. It confirms conformity to standards or categorisation criteria typically set by the sporting authority. At international and supra-national level, the FIA and FIM mandate what must be homologated, the FIA in its International Sporting Code and appendices. National sporting authorities such as Motorsport UK must adhere to these rules but may enforce additional or specific homologation rules applicable to their series or jurisdiction, however, unaffiliated series may set their own requirements.