GCT
- Alanine
- Cleethorpes
- Colonia Tovar dialect
- GCT 155mm
- Galapagos Conservation Trust
- Gauge Change Train
- Geometric complexity theory
- Germ cell tumor
- Ghazipur City railway station
- Giant-cell tumor of bone
- Global Champions Tour
- Gloucester County Times
- Glucose challenge test
- Government College of Technology (disambiguation)
- Grand Canyon Bar 10 Airport
- Grand Central Terminal
- Grand Chess Tour
- Granulosa cell tumor
- Great Coates railway station
- Green Card Test
- Greene County Tech School District
- Greenwich Civil Time
- Greenwood Community Theatre
- Grimsby
- Grimsby-Cleethorpes Transport
- Gwinnett County Transit