| Abbreviation | Definition |
|---|---|
| TLW | Tlawika ( Okwilteko) |
| TMH | Tamashek |
| TNE | Tropical Northeast Atlantic |
| TNJ | Thanjavur |
| TOG | Tonga ( Nyasa) |
| TOI | Tonga |
| TON | Tonga (Tonga Islands) |
| TQQ | East Somali: TUNNI |
| TQY | Torquay |
| TRU | Truk |
| TSC | Tshwa |
| TSI | Tsimshian |
| TSN | Tswana |
| TSO | Tsonga |
| TSW | Tswana |
| TUK | Turkmen |
| TUM | Tumbuka |
| TUR | Turkish |
| TUT | Altaic (Other) |
| TVL | TUVALUAN: A Language of Tuvalu |