GT3
GT3 may refer to:
- Porsche 911 GT3, a high performance version of the Porsche 911
- IMSA GT3 Cup Challenge, a one-make racing series featuring the Porsche 911 GT3
- IMSA GT3 Cup Challenge Canada, the Canadian subsidiary series
- IMSA GT3 Cup Challenge, a one-make racing series featuring the Porsche 911 GT3
- Gran Turismo 3: A-Spec a car racing game developed for the Sony PlayStation 2. Released in 2001.
- British Rail GT3 gas turbine locomotive
- Group GT3, a class of auto racing
- FIA GT3 European Championship, a series based on Group GT3