| TSU | Tabiteuea South, Republic of Kiribati 
| Others |
| TSU | Taiwan Solidarity Union
| Others |
| TSU | Taraba State University, Jalingo
| Others |
| TSU | Tbilisi State University
| Others |
| TSU | Technical Services Unit
| Others |
| TSU | Technical Support Unit
| Others |
| TSU | Technology And Software Unrestricted
| Others |
| TSU | Technology and Software Unrestricted License Exception
| Others |
| TSU | Tennessee State
| Others |
| TSU | Terran Special Unit
| Others |
| TSU | Texas Southern University
| Others |
| TSU | Texas State University
| Others |
| TSU | Thailand Southern University
| Others |
| TSU | The Save Ums
| Others |
| TSU | The Sniper Upstarts
| Others |
| TSU | The Start Up
| Others |
| TSU | Time Sharing User
| Others |
| TSU | Time Standard Unit
| Others |
| TSU | Tomsk State University
| Others |
| TSU | Top Soul University
| Others |
| TSU | Top Spin Underground
| Others |
| TSU | Toronto Secondary Unit
| Others |
| TSU | Tosa Skateboarders United
| Others |
| TSU | Total Stock Of Units
| Others |
| TSU | Touch Screen Unit
| Others |
| TSU | Trade Service Utility
| Others |
| TSU | Trek Smut University
| Others |
| TSU | Tri State University
| Others |
| TSU | Tri State Unlimited
| Others |
| TSU | Triple Sugar Urea
| Others |
| TSU | True Soldiers United
| Others |
| TSU | Tulsa-Sapulpa Union Railway
| Others |
| TSU | Tulsa-Sapulpa Union Railway Company
| Others |