GDD may mean:
- Game design document, a design document specific to video games.
- Gaseous detection device, a technology used with some electron microscopes and similar instruments
- Geographically Distributed Development
- Glaucoma drainage device
- Global Data Dictionary
- Global Drug Development
- Global developmental delay, a childhood medical disorder
- Goal-Directed Design, a user interface design method developed by Alan Cooper (software designer)
- Group delay dispersion (Group velocity dispersion), effect of a medium on an optical signal
- Google Developer Day, Google promotional events for developers
- Great Dragon's Dale, a Russian-language video gaming magazine
- Green Degree Directory
- Growing degree-day, a unit for measuring climatic warmth over a period of time