GCD may refer to:
- Greatest common divisor, concept used in mathematics
- Binary GCD algorithm, an algorithm which computes the greatest common divisor
- Greatest common divisor of two polynomials and is the largest polynomial that divides both and evenly
- Gardner Carton & Douglas, a former US law firm
- General content descriptor, a file format to describe content to wireless devices
- Grand Central Dispatch, computing technology from Apple Inc.
- Grand Comics Database, a database of comic book information
- Grant County Regional Airport (FAA identifier), an airport near John Day, Oregon, USA
- Griffith College Dublin, a private college in Dublin, Ireland
- Communist Party of China ("Gong Chan Dang" in Mandarin Chinese), the ruling party of the People's Republic of China