GTP may stand for:
Cars:
- A mid-level performance model on the Pontiac Grand Prix and the Pontiac G6
- Grand Touring Prototype, a race car category in IMSA GT Championship
Medicine, chemistry:
- Guanosine triphosphate, an organic chemical
- Good Tissue Practices, a medical standard
- Green tea polyphenols, a class of polyphenolic compounds found in green tea
Mathematics, computer science:
- Green's Theorem, one of several theorems that connect an integral in n-dimensional space with one in (n − 1)-dimensional space
- Go Text Protocol, a protocol for the board game of go
- GPRS Tunnelling Protocol, a group of protocols which carry GPRS data information over the UMTS and GSM networks
Locations:
- Global TransPark, an economic development area in Eastern North Carolina, USA
- Grand Trunk Pacific Railway reporting mark, a historical Canadian railway
Politics, education, communities:
- Government Transformation Programme, Malaysia
- Graduate Teacher Programme, a teacher education programme for UK trainee teachers
- GTPlanet, an online community dedicated to Gran Turismo
Psychology:
- Game Transfer Phenomena, a psychological phenomena
Zoology:
- Green Tree Python, a species of snake