| IATA | ICAO | Airport name | Location |
|---|
| UAM | PGUA | Andersen Air Force Base | Agana, Guam |
| UAO | KUAO | Aurora State Airport | Aurora, Oregon, United States |
| UAQ | SANU | Domingo Faustino Sarmiento Airport | San Juan Province, Argentina |
| UBA | SBUR | Uberaba Municipal Airport | Uberaba, Minas Gerais, Brazil |
| UBE | KUBE | Cumberland Municipal Airport | Cumberland, Wisconsin, United States |
| UBJ | BJDC | Yamaguchi Ube Airport | Ube, Yamaguchi Prefecture, Japan |
| UBP | VTUU | Ubon Ratchathani Airport | Ubon Ratchathani, Thailand |
| UBS | KUBS | Columbus-Lowndes County Airport | Columbus, Mississippi, United States |
| UBX | KUBX | Cuba Municipal Airport | Cuba, Missouri, United States |
| UCA | KUCA | Oneida County Airport | Utica, New York, United States |
| UCN | GLBU | Buchanan Airport | Buchanan, Liberia |
| UCP | KUCP | New Castle Municipal Airport | New Castle, Pennsylvania, United States |
| UCY | KUCY | Everett-Stewart Airport | Union City, Tennessee, United States |
| UDD | KUDD | Bermuda Dunes Airport | Palm Springs, California, United States |
| UDG | KUDG | Darlington County Jetport Airport | Darlington, South Carolina, United States |
| UDE | EHVK | Volkel Airport | Volkel, Netherlands |
| UDI | SBUL | Ten. Cel. Av. César Bombonato Airport | Uberlândia, Brazil |
| UEL | FQQL | Quelimane Airport | Quelimane, Mozambique |
| UES | KUES | Waukesha County Airport | Waukesha, Wisconsin, United States |
| UET | OPQT | Quetta International Airport | Quetta, Pakistan |
| UFA | UWUU | Ufa Airport | Ufa, Russia |
| UGA | ZMBN | Bulgan Airport | Bulgan, Bulgan, Mongolia |
| UGB | | Ugashik Bay Airport | Pilot Point, Alaska, United States |
| UGN | KUGN | Waukegan Regional Airport | Chicago/Waukegan, Illinois, United States |
| UHF | EGUA | RAF Upper Heyford | Upper Heyford, England, United Kingdom |
| UIB | SKUI | El Caraño Airport | Quibdó, Colombia |
| UIH | VVPC | Phu Cat Airport | Qui Nhon, Binh Dinh, Vietnam |
| UIL | KUIL | Quillayute Airport | Forks, Washington, United States |
| UIN | KUIN | Quincy Regional Airport (Baldwin Field) | Quincy, Illinois, United States |
| UIO | SEQU | Mariscal Sucre International Airport | Quito, Ecuador |
| UIP | LFRQ | Quimper - Cornouaille Airport | Quimper, France |
| UKF | KUKF | Wilkes County Airport | North Wilkesboro, North Carolina, United States |
| UKI | KUKI | Ukiah Municipal Airport | Ukiah, California, United States |
| UKK | UASK | Oskemen Airport | Oskemen, Kazakhstan |
| UKL | KUKL | Coffey County Airport | Burlington, Kansas, United States |
| UKS | UKFB | Belbek Airport | Sevastopol, Autonomous Republic of Crimea, Ukraine |
| UKT | KUKT | Quakertown Airport | Quakertown, Pennsylvania, United States |
| ULG | ZMUL | Ölgii Airport | Bayan-Ölgii Province, Mongolia |
| ULM | KULM | New Ulm Municipal Airport | New Ulm, Minnesota, United States |
| ULN | ZMUB | Chinggis Khaan International Airport | Ulan Bator, Mongolia |
| ULO | ZMUG | Ulaangom Airport | Ulaangom, Uvs Province, Mongolia |
| ULS | KULS | Ulysses Airport | Ulysses, Kansas, United States |
| ULY | UWLW | Ulyanovsk Vostochny Airport | Ulyanovsk, Russia |
| UMD | BGUM | Uummannaq Heliport | Uummannaq |
| UME | ESNU | Alvik Airport | Umea, Sweden |
| UMM | PAST | Summit Airport (Alaska) | Summit, Alaska, United States |
| UMP | KUMP | Indianapolis Metropolitan Airport | Indianapolis, Indiana, United States |
| UMT | PAUM | Umiat Airport | Umiat, Alaska, United States |
| UNC | | Unguía Airport | Unguía, Colombia |
| UND | OAUZ | Kunduz Airport | Kunduz, Afghanistan |
| UNI | KUNI | Ohio University Snyder Field | Athens/Albany, Ohio, United States |
| UNI | TVSU | Union Island Airport | Union Island, Saint Vincent and the Grenadines |
| UNK | PAUN | Unalakleet Airport | Unalakleet, Alaska, United States |
| UNN | | Ranong Airport | Ranong, Thailand |
| UNR | ZMUH | Öndörkhaan Airport | Öndörkhaan, Khentii, Mongolia |
| UNU | KUNU | Dodge County Airport | Juneau, Wisconsin, United States |
| UOS | KUOS | Franklin County Airport | Sewanee, Tennessee, United States |
| UOX | KUOX | University-Oxford Airport | Oxford, Mississippi, United States |
| UPG | WAAA | Sultan Hasanuddin International Airport | Makassar, Indonesia |
| UPK | BGKL | Upernavik Kujalleq Heliport | Upernavik Kujalleq, Greenland |
| UPL | MRUP | Upala Airport | Upala, Costa Rica |
| UPN | MMPN | Lic. y Gen. Ignacio López Rayón International Airport | Uruapan, Michoacán, Mexico |
| UPP | PHUP | Upolu Airport | Hawi, Hawaii, United States |
| URA | UARR | Oral Ak Zhol Airport | Oral, Kazakhstan |
| URC | ZWWW | Diwopu Airport | Urumqi, China |
| URE | EEKE | Kuressaare Airport | Kuressaare, Saaremaa, Estonia |
| URG | SBUG | Aeroporto Internacional Rubem Berta | Uruguaiana, Rio Grande do Sul, Brazil |
| URT | VTSB | Surat Thani Airport | Surat Thani, Thailand |
| USE | KUSE | Fulton County Airport | Wauseon, Ohio, United States |
| USH | SAWH | Ushuaia - Malvinas Argentinas International Airport | Ushuaia, Argentina |
| USI | SYMB | Mabaruma Airport | Mabaruma, Guyana |
| USM | VTSM | Samui Airport | Surat Thani, Thailand |
| USQ | LTBO | Usak Airport | Usak, Turkey |
| UST | KSGJ | St. Augustine Airport | St. Augustine, Florida, United States |
| UTA | KUTA | Tunica Municipal Airport | Tunica, Mississippi, United States |
| UTN | FAUP | Upington Airport | Upington, South Africa |
| UTO | PAIM | Indian Mountain LRRS | Utopia Creek, Alaska, United States |
| UTP | VTBU | U-Tapao International Airport | Rayong, Thailand |
| UTS | KUTS | Huntsville Municipal Airport | Huntsville, Texas, United States |
| UUK | PAKU | Ugnu-Kuparuk Airport | Kuparuk, Alaska, United States |
| UUO | PAUO | Willow Airport | Willow, Alaska, United States |
| UUS | UHSS | Yuzhno - Sakhalinsk Airport | Yuzhno-Sakhalinsk, Russia |
| UUU | KUUU | Newport State Airport (Rhode Island) | Newport, Rhode Island, United States |
| UUV | KUUV | Sullivan Regional Airport | Sullivan, Missouri, United States |
| UVA | KUVA | Garner Field | Uvalde, Texas, United States |
| UVF | TLPL | Hewanorra International Airport | Vieux-Fort, Saint Lucia |
| UWL | KUWL | New Castle-Henry County Municipal Airport | New Castle, Indiana, United States |
| UYF | KUYF | Madison County Airport | London, Ohio, United States |
| UYL | HSNN | Nyala Airport | Nyala, Sudan |
| UZA | KUZA | Rock Hill/York County Airport (Bryant Field) | Rock Hill, South Carolina, United States |
| UZC | LYUZ | Užice-Ponikve Airport | Užice, Serbia |