| University of Central Arkansas | Academic & Science |
| University of Central Asia (Khorog, Tajikistan) | Academic & Science |
| University of Central Asia | Academic & Science |
| University City Associates | Academic & Science |
| University for the Creative Arts | Academic & Science |
| University Center for the Arts | Academic & Science |
| Utica (ny) | Airport Code |
| Unified Corporate Authority | Business |
| United Canadian Alliance | Business |
| Unified Caring Association | Business |
| Underground Contractors Association | Business |
| United Cheerleaders of America | Community |
| Uttarakhand Cultural Association, Canada | Community |
| Universal Cheerleader Association, Cheerleader Training Organization founded in 1974, (uca.varsity.com) | Community |
| Universal Cheerleaders Association | Community |
| Union de Cooperativas Agropecuarias | Community |
| United Court of Austin, Inc. | Community |
| United Capoeira Association | Community |
| Unknown Chinese Artists | Community |
| United Christian Academy | Community |
| Utility Communication Architecture | Computer Hardware |
| Unauthorized Computer Access | Computing |
| United Computer Accessories | Computing |
| United Computer Associates | Computing |
| Unicast Address | Computing |
| UCA Coin | Cryptocurrency |
| Universal College Application | Educational Institute |
| Universal College Applicaton | Educational Institute |
| Utah Chess Association | General |
| United Canine Association | General |
| Unicode Collation Algorithm | General |
| Underground Construction Association | General |
| Utah Consolidated Application | General |
| Under Color Addition | General |
| Under Construction Always | General |
| Urban Core Area | General |
| Unique Common Ancestor | General |
| Universidad Católica Argentina | General |
| Usine de Construction Aéronautique | General |
| Utah Code Annotated | General |
| Unique Compatibility Additives | General |
| United Chinese Americans | General |
| Utility Cost Adjustment | General |
| Upper Control Arm | General |
| Used Car Awards | General |
| Utah Corvette Association | General |
| Undefinitized Contract Action | Governmental |
| Union Council Administration | Governmental |
| UCHANA | Indian Railway Station |
| Unión de Campesinos Asturianos | International |
| Universidad CentroAmericana José Simeón Cañas | International |
| User Created Animal | Medical |
| Urgent Care Administrator | Medical |
| Under Chair Activities | Messaging |
| Unenclosed Covered Area | Military and Defence |
| Utility Communications Architecture | Networking |
| Utica, New York USA | Regional |
| United Cheerleading Association | Sports |