UDR
- Decision Review System
- Democratic Union for the Republic
- Nine Daughters of Ægir
- OpenMP
- U.D.R.
- UDR, Inc.
- Udaipur Airport
- Ulster Defence Regiment
- Union for Democracy and the Republic (Chad)
- Union of Democrats for the Republic
- Union of the Right for the Republic
- Universal dielectric response
- Univision Deportes Radio
- União Democrática Ruralista
- Untethered dead reckoning