SRO GT4 is a class of grand tourer racing cars maintained by the SRO Motorsports Group that race in various Auto racing series across the globe. It is an entry-level class aimed at amateur drivers. GT4 cars are production-based vehicles with a few modifications for racing. The cars are closer to their road legal counterparts than most other GT racing classes; they are also one of the least powerful GT categories.^[1][2] The class uses a balance of performance system to provide close competition between different race cars.

The GT4 category was founded by the SRO at the end of 2006, and first introduced in 2007, racing in the GT4 European Cup as a cheaper alternative for GT3 racing.^[3] The category was also added to the British GT Championship in 2008.^[4] The SRO also founded the Dutch GT Championship in 2009.^[5] The GT4 class was also adapted by several other small national championships.

After an unsuccessful attempt to expand the category in 2012, the SRO introduced the GT4 European Trophy, consisting of five rounds from existing European Championships.^[6] This replaced the GT4 European Cup. In 2014, this series merged with the Dutch GT4 Championship to form the GT4 European series.^[7]

Due to a low number of entries, the SRO announced that the GT4 European series would be split into two championships, the GT4 European Series Northern Cup and the GT4 European Series Southern Cup.^[8] The Northern Cup would turn back into the GT4 European series, while the Southern Cup would turn into the FFSA GT Championship.

As of April 2024, over 40 vehicles have gone through the homologation project with the RACB. GT4 cars can either directly be built by the automotive manufacturer, or by race teams and tuning companies.

SRO GT4 cars have been either exclusive to or in a distinct class in each of the following series:

Bold indicates an active series that currently uses SRO GT4 cars.

• GT4 European Series
• 24H Series
• Nürburgring Langstrecken series
• British GT Championship
• ADAC GT4 Germany
• FFSA GT Championship

• GT4 America Series
• GT America Series
• Michelin Pilot Challenge

• GT World Challenge Asia
• Dutch GT4 Championship
• IMSA VP Racing SportsCar Challenge
• Australian GT Championship
• DTM Trophy
• GT4 Winter Series standalone for 2023 onwards | GT Winter Series 2019-2022
• Endurance Brasil
• Italian GT Championship
• Super Taikyu Series
• GT Cup Championship

Additionally, the following series allow SRO GT4 cars to participate alongside other competitors:

• Supercar Challenge
• Belcar
• GT Cup Open Europe
• British Endurance Championship
• Iberian Supercars