| Acronym | Definition |
|---|
| TCN | transparent content negotiation |
| TCN | Tetracycline |
| TCN | Third Country National(s) |
| TCN | Topology Change Notification |
| TCN | Transportation Control Number |
| TCN | Telecommunications Network |
| TCN | The Comcast Network |
| TCN | Train Communication Network |
| TCN | Transaction Control Number |
| TCN | The Cartoon Network |
| TCN | Tactical Component Network |
| TCN | Tactical Air Navigation (TACAN) |
| TCN | Troop Contributing Nations |
| TCN | Think College Now |
| TCN | Terminal Control Number (US IRS) |
| TCN | Triathlon Club Nantais (Nantes, France) |
| TCN | Terrestrial Cosmogenic Nuclide (earth science) |
| TCN | Take Care Now Ltd (UK healthcare provider) |
| TCN | Traditional Care Network (healthcare program) |
| TCN | Toronto Community News (Canada) |
| TCN | Toraja Cyber News (Indonesian online media) |
| TCN | Title Control Number (library cataloging) |
| TCN | Transforming Churches Network (Missouri) |
| TCN | Test Change Notice |
| TCN | Terrestrial Communications Network |
| TCN | Third Country Nation |
| TCN | Traffic Control Number |
| TCN | Tactical Control Network |
| TCN | The Claymore Nation (gaming) |
| TCN | Test Case Notation (ISO) |
| TCN | Technician Corporation |
| TCN | Task Control Number |
| TCN | Theater Communications Network |
| TCN | Temporary Change Notification |
| TCN | Terran Confederation News |
| TCN | Travel Card Number (Sprint) |
| TCN | Technical Change Notice |
| TCN | Trans-Country National |
| TCN | Team Crip Nasty (hunting group; Michigan) |
| TCN | Travel Change Notification |
| TCN | Tracing Change Notice |
| TCN | Technical Cooperation Agency |
| TCN | Turbo Chat Network |
| TCN | Troubleshooting Cisco Network |
| TCN | Transaction Control Network |
| TCN | The Continuum Network (Toronto, Ontario, Canada) |
| TCN | Truck Consignment Note (freight shipping) |
| TCN | Tri-County North (Ohio school district) |
| TCN | Telephone Computer Network, Inc. (Utah) |
| TCN | Trigeminocervical Nucleus |