| .su | former Soviet Union | | Still in use. |
| .tc | Turks and Caicos Islands | | |
| .tf | French Southern and Antarctic Lands | | Seldom used. |
| .tj | Tajikistan | | |
| .tk | Tokelau | | Also used as a free domain service to the public. |
| .tm | Turkmenistan | | |
| .to | Tonga | | Often used unofficially for Toronto or Tokyo |
| .tr | Turkey | | |
| .tv | Tuvalu | | Used as an abbreviation of television, the domain is currently operated by dotTV, a VeriSign company; the Tuvalu government owns twenty percent of the company. |
| .tw | Republic of China (Taiwan) | | Registration allowed worldwide, local presence not required. |
| .ua | Ukraine | | |
| .uk | United Kingdom | | ISO 3166-1 code is gb, but .uk is used for historical reasons |
| .us | United States of America | | (Commonly used by U.S. State and local governments instead of .gov TLD.) |
| .uy | Uruguay | | |
| .uz | Uzbekistan | | |
| .va | Vatican City | | |
| .vc | Saint Vincent and the Grenadines | | |
| .ve | Venezuela | | |
| .vg | British Virgin Islands | | |
| .ws | Samoa | Formerly Western Samoa | |
