- UNICUS Incorporated
- Unified Government of Wyandotte County
- Unifirst
- Unifocus
- Union Bank and Trust Credit Administration
- Union Center National Bank
- Union County
- Union County
- Union County Board of Commissioners
- Union County Care Committee
- Union Hospital
- Union Hospital
- Union Hospital
- Union Pacific Railroad
- Union Planters Corp
- Union Switch and Signal
- Unique Paving Materials Corporation
- Unisys
- Unitech
- United American of Tennessee
- United Appeals of Hardin County
- United Auto Workers Retired Workers Department UAW)
- United Auto Workers, Local 2000
- United Auto Workers, Local 425
- United Autoworkers
- United Bank of Philadelphia
- United Blood Services
- United Cerebral Palsy Society of Pittsburgh
- United Church Homes
- United Church of Christ Homes
- United Dominion Realty Trust
- United Fund of Cuivre Township, Inc.
- United Fund of Westfield
- United Health Care
- United Health Care of River Valley
- United Health Services Hospitals
- United Healthcare
- United Helpers Management Co.
- United Labor Agency
- United Medical Center
- United Memorial Medical Center
- United Methodist Association
- United Methodist Homes of New Jersey
- United Mine Workers of America, District 2
- United Ministries
- United Neighborhood Health Services
- United Network for Organ Sharing UNOS)
- United Parcel Service
- United Patient Care Products Incorporated
- United Regional Health Care System