UDC
- Cameroon Democratic Union
- Central African Democratic Union
- Christian Democratic Union (Dominican Republic)
- Christian Democratic Union (Ecuador)
- Democratic Union of Catalonia
- Neo-Confederates
- Nicaraguan Christian Democratic Union
- Swiss People's Party
- UDC Finance
- UDC Homes
- Uganda Development Corporation
- Umbrella for Democratic Change
- Unified Development Code
- Union of Democratic Control
- Union of the Centre (1993)
- Union of the Centre (2002)
- Union of the Right and Centre
- United Daughters of the Confederacy
- Universal Decimal Classification
- University Development Center
- University of A Coruña
- University of the District of Columbia
- Urban Development Corporation
- Urban and rural districts (Ireland)
- Urban district (England and Wales)
- Utah Data Center
- Utah Department of Corrections
- Utility Data Center