| Acronym | Definition |
|---|
| TNI | Tahitian Noni International (beverage company; Orem, UT) |
| TNI | Transnational Institute (Amsterdam, Netherlands) |
| TNI | Thai-Nichi Institute of Technology (Bangkok, Thailand) |
| TNI | Targul National Imobiliar (Romanian: National Real Estate Fair) |
| TNI | Troponin I |
| TNI | Tentara Nasional Indonesia |
| TNI | Trusted Network Interpretation |
| TNI | The National Investor (United Arab Emirates) |
| TNI | The New Information |
| TNI | The Neuroscience Institute (Cincinnati, OH) |
| TNI | Transition Networks, Inc. |
| TNI | Telephone Network Interface |
| TNI | Training Needs Identification |
| TNI | Tourisme News International (French: Tourism News International; UK; est. 2005) |
| TNI | Telephone Number Inventory |
| TNI | Tejas New Instruction (memory protocol, computing) |
| TNI | Tiny Natural Inclusion (philatelic imperfection) |
| TNI | Telecommunications & Navigation Institute |