| USI | Mabaruma, Guyana 
| Others |
| USI | Ultimate Spot In Indiana
| Others |
| USI | Ultra Services Inc
| Others |
| USI | Ultrasonic Systems Inc
| Others |
| USI | Umbra Space Industries
| Others |
| USI | Un Satisfactory Inspection
| Others |
| USI | Un Satisfactory Inspections
| Others |
| USI | Underground Systems Inc
| Others |
| USI | Understand Service and Innovate
| Others |
| USI | Understand Service Innovate
| Others |
| USI | Unified Space Intelligence
| Others |
| USI | Union of students in Ireland
| Others |
| USI | Unique Student Identification
| Others |
| USI | Unique Student Identifier
| Others |
| USI | Unique Superannuation Identifier
| Others |
| USI | United Services Inc
| Others |
| USI | United Sportsmen Incorporated
| Others |
| USI | United States History One
| Others |
| USI | United States Of India
| Others |
| USI | United Systems Institute
| Others |
| USI | Unitray Systems Inc
| Others |
| USI | Unitray Systems, Inc.
| Others |
| USI | Universal Scientific Industrial
| Others |
| USI | Universal Security Instruments
| Others |
| USI | Universal Serial Interface
| Others |
| USI | Universal Sim Interface
| Others |
| USI | Universal Solutions International
| Others |
| USI | Universal Speech Interface
| Others |
| USI | Universal Stylus Initiative
| Others |
| USI | Universal Swap Identifier
| Others |
| USI | Universal Systems, Inc.
| Others |
| USI | University of Southern Indiana
| Others |
| USI | University of Southern Indiana ( Evansville)
| Others |
| USI | Unmanned Safety Institute
| Others |
| USI | Update Software Identity
| Others |
| USI | Urological Society of India
| Others |
| USI | Usb Interface
| Others |
| USI | User Service Information
| Others |
| USI | User Side Interface
| Others |
| USI | User Specific Interface
| Others |
| USI | User System Interface
| Others |