word | | Country name |
| form | Tuvalu | conventional long form: none conventional short form: Tuvalu local long form: none local short form: Tuvalu former: Ellice Islands note: "Tuvalu" means "group of eight," referring to the country's eight traditionally ... |
| form | Uganda | conventional long form: Republic of Uganda conventional short form: Uganda |
| form | Ukraine | conventional long form: none conventional short form: Ukraine local long form: none local short form: Ukrayina former: Ukrainian National Republic, Ukrainian State, Ukrainian Soviet Socialist Republic |
| form | United Arab Emirates | conventional long form: United Arab Emirates conventional short form: none local long form: Al Imarat al Arabiyah al Muttahidah local short form: none former: Trucial Oman, Trucial States abbreviation: UAE |
| form | United Kingdom | conventional long form: United Kingdom of Great Britain and Northern Ireland; note - Great Britain includes England, Scotland, and Wales conventional short form: United Kingdom abbreviation: UK |
| form | United States | conventional long form: United States of America conventional short form: United States abbreviation: US or USA |
| form | United States Pacific Island Wildlife Refuges | conventional long form: none conventional short form: Baker Island; Howland Island; Jarvis Island; Johnston Atoll; Kingman Reef; Midway Islands; Palmyra Atoll |
| form | Uruguay | conventional long form: Oriental Republic of Uruguay conventional short form: Uruguay local long form: Republica Oriental del Uruguay local short form: Uruguay former: Banda Oriental, Cisplatine Province |
| form | Uzbekistan | conventional long form: Republic of Uzbekistan conventional short form: Uzbekistan local long form: Ozbekiston Respublikasi local short form: Ozbekiston former: Uzbek Soviet Socialist Republic |
| form | Vanuatu | conventional long form: Republic of Vanuatu conventional short form: Vanuatu local long form: Ripablik blong Vanuatu local short form: Vanuatu former: New Hebrides |