| Acronym | Meaning |
| TRN | Target Reference Number |
| TRN | Task Requirement Notice |
| TRN | Tax Research Network (UK) |
| TRN | Taxpayer Registration Number (Jamaica) |
| TRN | Terrain-Reference Navigation |
| TRN | Titre de Reconnaissance de la Nation (French: Full Recognition of the Nation) |
| TRN | Training Document (TMINS) |
| TRN | Transit Routing Number |
| TRN | Transport |
| TRN | Travel Record Number |
| TRN | Treasury Reserve Note (US Treasury) |
| TRN | Turnaround |