| Code Name | City Name | Airport Name | Airport Country |
| UAC | San Luis Rio Colorado | San Luis Rio Colorado | Mexico |
| UAE | Mount Aue | Mount Aue | Papua New Guinea |
| UAH | Ua Huka | Ua Huka | French Polynesia |
| UAI | Suai | Suai | Indonesia |
| UAK | Narsarsuaq | Narsarsuaq | Greenland |
| UAL | Luau | Luau | Angola |
| UAM | Guam | Anderson AFB | Guam |
| UAP | Ua Pou | Ua Pou | French Polynesia |
| UAQ | San Juan | San Juan | Argentina |
| UAS | Samburu | Samburu | Kenya |
| UAX | Uaxactun | Uaxactun | Guatemala |
| UBA | Uberaba | Uberaba | Brazil |
| UBB | Mabuiag Island | Mabuiag Island | Australia |
| UBI | Buin | Buin | Papua New Guinea |
| UBJ | Ube | Ube | Japan |
| UBP | Ubon Ratchathani | Muang Ubon | Thailand |
| UBR | Ubrub | Ubrub | Indonesia |
| UBS | Columbus | Lowndes County | USA, MS |
| UBT | Ubatuba | Ubatuba | Brazil |
| UBU | Kalumburu | Kalumburu | Australia |
| UCA | Utica | Oneida County | USA, NY |
| UCC | Yucca Flat | Yucca Flat | USA, NV |
| UCE | Eunice | Eunice | USA, LA |
| UCK | Lutsk | Lutsk | Ukraine |
| UCN | Buchanan | Buchanan | Liberia |
| UCT | Ukhta | Ukhta | Russia |
| UCY | Union City | Everett-Stewart | USA, TN |
| UDA | Undarra | Undarra | Australia |
| UDD | Palm Springs | Bermuda Dunes | USA, CA |
| UDE | Uden | Volkel | Netherlands |
| UDI | Uberlandia | Eduardo Gomes | Brazil |
| UDJ | Uzhgorod | Uzhgorod | Ukraine |
| UDN | Udine | Airfield | Italy |
| UDO | Udomxay | Udomxay | Lao PDR |
| UDR | Udaipur | Dabok | India |
| UEE | Queenstown | Queenstown | Australia |
| UEL | Quelimane | Quelimane | Mozambique |
| UEO | Kumejima | Kumejima | Japan |
| UES | Waukesha | Waukesha | USA, WI |
| UET | Quetta | Quetta | Pakistan |
| UFA | Ufa | Ufa | Russia |
| UGA | Bulgan | Bulgan | Mongolia |
| UGB | Pilot Point | Ugashik Bay | USA, AK |
| UGC | Urgench | Urgench | Uzbekistan |
| UGI | Uganik | Uganik | USA, AK |
| UGN | Waukegan | Memorial | USA, IL |
| UGO | Uige | Uige | Angola |
| UGS | Ugashik | Ugashik | USA, AK |
| UGU | Zugapa | Zugapa | Indonesia |
| UHE | Uherske Hradiste | Uherske Hradiste | Czech Republic |
| UHF | Upper Heyford | RAF Station | United Kingdom |
| UIB | Quibdo | Quibdo | Colombia |
| UIH | Qui Nhon | Qui Nhon | Viet Nam |
| UII | Utila | Utila | Honduras |
| UIK | Ust-Ilimsk | Ust-Ilimsk | Russia |
| UIL | Quillayute | Quillayute State | USA, WA |
| UIN | Quincy | Municipal | USA, IL |
| UIO | Quito | Mariscal Sucre Airport | Ecuador |
| UIP | Quimper | Pluguffan | France |
| UIQ | Quine Hill | Quine Hill | Vanuatu |
| UIR | Quirindi | Quirindi | Australia |
| UIT | Jaluit Island | Jaluit Island | Marshall Islands |
| UIZ | Utica | Berz-Macomb | USA, MI |
| UJE | Ujae Island | Ujae Island | Marshall Islands |
| UKA | Ukunda | Ukunda | Kenya |
| UKB | Kobe | Kobe | Japan |
| UKI | Ukiah | Ukiah | USA, CA |
| UKK | Ust-Kamenogorsk | Ust-Kamenogorsk | Kazakhstan |
| UKN | Waukon | Municipal | USA, IA |
| UKR | Mukeiras | Mukeiras | Yemen |
| UKT | Quakertown | Upper Bucks | USA, PA |
| UKU | Nuku | Nuku | Papua New Guinea |
| UKX | Ust-Kut | Ust-Kut | Russia |
| UKY | Kyoto | Kyoto | Japan |
| ULA | San Julian | San Julian | Argentina |
| ULB | Ulei | Ulei | Vanuatu |
| ULC | Santiago | Los Cerrillos | Chile |
| ULD | Ulundi | Ulundi | South Africa |
| ULE | Sule | Sule | Papua New Guinea |
| ULG | Ulgit | Ulgit | Mongolia |
| ULI | Ulithi | Ulithi | Micronesia |
| ULL | Mull | Mull | United Kingdom |
| ULM | New Ulm | New Ulm | USA, MN |
| ULN | Ulaanbaatar | Buyant Uhaa | Mongolia |
| ULO | Ulaangom | Ulaangom | Mongolia |
| ULP | Quilpie | Quilpie | Australia |
| ULQ | Tulua | Farfan | Colombia |
| ULS | Mulatos | Mulatos | Colombia |
| ULU | Gulu | Gulu | Uganda |
| ULX | Ulusaba | Ulusaba | South Africa |
| ULY | Ulyanovsk | Ulyanovsk | Russia |
| ULZ | Uliastai | Uliastai | Mongolia |
| UMA | Punta De Maisi | Punta De Maisi | Cuba |
| UMB | Umnak Island | North Shore | USA, AK |
| UMC | Umba | Umba | Papua New Guinea |
| UMD | Uummannaq | Uummannaq | Greenland |
| UME | Umea | Umea | Sweden |
| UMI | Quincemil | Quincemil | Peru |
| UMM | Summit | Summit | USA, AK |
| UMR | Woomera | Woomera | Australia |
| UMT | Umiat | Umiat | USA, AK |
| UMU | Umuarama | Ernesto Geisel | Brazil |
| UMY | Sumy | Sumy | Ukraine |
| UNA | Una | Una | Brazil |
| UNC | Unguia | Unguia | Colombia |
| UND | Kunduz | Kunduz | Afghanistan |
| UNE | Qachas Nek | Qachas Nek | Lesotho |
| UNG | Kiunga | Kiunga | Papua New Guinea |
| UNI | Union Island | Union Island | Saint Vincent and the Grenadines |
| UNK | Unalakleet | Unalakleet | USA, AK |
| UNN | Ranong | Ranong | Thailand |
| UNR | Underkhaan | Underkhaan | Mongolia |
| UNS | Umnak Island | Umnak | USA, AK |
| UNT | Unst Shetland Is | Baltasound | United Kingdom |
| UNU | Juneau | Dodge County | USA, WI |
| UOL | Buol | Buol | Indonesia |
| UON | Muong Sai | Muong Sai | Lao PDR |
| UOS | Sewanee | Franklin County | USA, TN |
| UOX | Oxford | University-Oxford | USA, MS |
| UPA | Punta Alegre | Punta Alegre | Cuba |
| UPC | Puerto La Cruz | Puerto La Cruz | Spain |
| UPF | Pforzheim | Pforzheim | Germany |
| UPG | Ujung Pandang | Hasanudin | Indonesia |
| UPL | Upala | Upala | Costa Rica |
| UPN | Uruapan | Uruapan | Mexico |
| UPP | Upolu Point | Upolu Point | USA, HI |
| UPR | Upiara | Upiara | Papua New Guinea |
| UPV | Upavon | Upavon | United Kingdom |
| UQE | Queen | Queen | USA, AK |
| URA | Uralsk | Uralsk | Kazakhstan |
| URB | Urubupunga | Ernesto Pochler | Brazil |
| URC | Urumqi | Urumqi | PR China |
| URE | Kuressaare | Kuressaare | Ethiopia |
| URG | Uruguaiana | Ruben Berta | Brazil |
| URI | Uribe | Uribe | Colombia |
| URJ | Uraj | Uraj | Russia |
| URM | Uriman | Uriman | Venezuela |
| URN | Urgoon | Urgoon | Afghanistan |
| URO | Rouen | Boos | France |
| URR | Urrao | Urrao | Colombia |
| URS | Kursk | Kursk | Russia |
| URT | Surat Thani | Surat Thani | Thailand |
| URU | Uroubi | Uroubi | Papua New Guinea |
| URY | Gurayat | Gurayat | Saudi Arabia |
| URZ | Uruzgan | Uruzgan | Afghanistan |
| USH | Ushuaia | Islas Malvinas | Argentina |
| USI | Mabaruma | Mabaruma | Guyana |
| USK | Usinsk | Usinsk | Russia |
| USL | Useless Loop | Useless Loop | Australia |
| USM | Koh Samui | Koh Samui | Thailand |
| USN | Ulsan | Ulsan | South Korea |
| USO | Usino | Usino | Papua New Guinea |
| USQ | Usak | Usak | Turkey |
| USS | Sancti Spiritus | Sancti Spiritus | Cuba |
| UST | St Augustine | St Augustine | USA, FL |
| USU | Busuanga | Busuanga | Philippines |
| UTA | Mutare | Mutare | Zimbabwe |
| UTB | Muttaburra | Muttaburra | Australia |
| UTC | Utrecht | Soesterberg | Netherlands |
| UTD | Nutwood Downs | Nutwood Downs | Australia |
| UTE | Butterworth | Butterworth | South Africa |
| UTG | Quthing | Quthing | Lesotho |
| UTH | Udon Thani | Udon Thani | Thailand |
| UTI | Kouvola | Utti | Finland |
| UTK | Utirik Island | Utirik Island | Marshall Islands |
| UTL | Torremolinos | Torremolinos | Spain |
| UTN | Upington | Upington | South Africa |
| UTO | Utopia Creek | Indian Mountain AFS | USA, AK |
| UTP | Utapao | Utapao | Thailand |
| UTR | Uttaradit | Uttaradit | Thailand |
| UTT | Umtata | Umtata | South Africa |
| UTU | Ustupo | Ustupo | Panama |
| UTW | Queenstown | Queenstown | South Africa |
| UUA | Bugulma | Bugulma | Russia |
| UUD | Ulan-Ude | Ulan-Ude | Russia |
| UUK | Kuparuk | Kuparuk | USA, AK |
| UUN | Baruun-Urt | Baruun-Urt | Mongolia |
| UUS | Yuzhno-Sakhalinsk | Yuzhno-Sakhalinsk | Russia |
| UUU | Manumu | Manumu | Papua New Guinea |
| UVA | Uvalde | Garner Fld | USA, TX |
| UVE | Ouvea | Ouvea | New Caledonia |
| UVF | Saint Lucia | Hewanorra | Saint Lucia |
| UVL | Kharga | Kharga | Egypt |
| UVO | Uvol | Uvol | Papua New Guinea |
| UWA | Ware | Ware | USA, MA |
| UWE | Wiesbaden | Metropolitan Area | Germany |
| UYL | Nyala | Nyala | Sudan |
| UYN | Yulin | Yulin | PR China |
| UZH | Unayzah | Unayzah | Saudi Arabia |
| UZU | Curuzu Cuatia | Curuzu Cuatia | Argentina |