UDP
- Democratic and Popular Union
- Diego Portales University
- Popular Democratic Union (Portugal)
- Ulster Democratic Party
- Undecaprenyl phosphate
- Union for Democracy and Progress
- Unit Deployment Program
- Unitary development plan
- United Democratic Party (disambiguation)
- Universality–diversity paradigm
- Uridine diphosphate
- Usenet Death Penalty
- User Datagram Protocol
- Verilog