| IATA |
ICAO |
Airport name |
Location served |
|---|
| -OA- |
| OAA | OASH | Forward Operating Base Shank | Gardez, Afghanistan |
| OAG | YORG | Orange Airport[1] | Orange, New South Wales, Australia |
| OAH | OASD | Shindand Air Base | Shindand, Afghanistan |
| OAI | OAIX | Bagram Airfield | Bagram, Afghanistan |
| OAJ | KOAJ | Albert J. Ellis Airport | Jacksonville, North Carolina, United States |
| OAK | KOAK | Oakland International Airport | Oakland, California, United States |
| OAL | SSKW | Capital do Café Airport[1] | Cacoal, Rondônia, Brazil |
| OAM | NZOU | Oamaru Airport | Oamaru, New Zealand |
| OAN | MHEA | El Arrayán Airport[1] | Olanchito, Honduras |
| OAR | KOAR | Marina Municipal Airport | Monterey / Marina, California, United States |
| OAS | OASA | Sharana Airstrip / Forward Operating Base Sharana | Sharana, Afghanistan |
| OAX | MMOX | Xoxocotlán International Airport | Oaxaca de Juárez, Oaxaca, Mexico |
| OAZ | OAZI | Camp Bastion Air Base | Lashkar Gah, Afghanistan |
| -OB- |
| OBA | | Oban Airport[1] | Oban, Queensland, Australia |
| OBC | HDOB | Obock Airport | Obock, Djibouti |
| OBD | | Obano Airport | Obano, Indonesia |
| OBE | KOBE | Okeechobee County Airport | Okeechobee, Florida, United States |
| OBF | EDMO | Oberpfaffenhofen Airport | Oberpfaffenhofen, Bavaria, Germany |
| OBI | SBTI | Óbidos Airport[1] | Óbidos, Pará, Brazil |
| OBL | EBZR | Oostmalle Airfield | Zoersel, Belgium |
| OBM | | Morobe Airport[1] | Morobe, Papua New Guinea |
| OBN | EGEO | Oban Airport[1] (North Connel Airport) | Oban, Scotland, United Kingdom |
| OBO | RJCB | Tokachi–Obihiro Airport | Obihiro, Hokkaido, Japan |
| OBS | LFHO | Aubenas Aerodrome[1] (Ardèche Méridionale Aerodrome) | Aubenas, Rhône-Alpes, France |
| OBU | PAOB | Kobuk Airport | Kobuk, Alaska, United States |
| OBX | AYOB | Obo Airport | Obo, Papua New Guinea |
| -OC- |
| OCA | | Ocean Reef Club Airport (FAA: 07FA) | Key Largo, Florida, United States |
| OCC | SECO | Francisco de Orellana Airport | Puerto Francisco de Orellana (Coca), Ecuador |
| OCF | KOCF | Ocala International Airport (Jim Taylor Field) | Ocala, Florida, United States |
| OCH | KOCH | A.L. Mangham Jr. Regional Airport | Nacogdoches, Texas, United States |
| OCJ | MKBS | Ian Fleming International Airport | Ocho Rios, Jamaica |
| OCM | YBGD | Boolgeeda Airport[1] | Boolgeeda, Western Australia, Australia |
| OCN | KOKB | Oceanside Municipal Airport (FAA: OKB) | Oceanside, California, United States |
| OCS | | Corisco International Airport[1] | Corisco Island, Equatorial Guinea |
| OCV | SKOC | Aguas Claras Airport[1] | Ocaña, Colombia |
| OCW | KOCW | Washington–Warren Airport (Warren Field) | Washington, North Carolina, United States |
| -OD- |
| ODA | FEFW | Ouadda Airport[1] | Ouadda, Central African Republic |
| ODB | LEBA | Córdoba Airport | Córdoba, Andalusia, Spain |
| ODC | | Oakdale Airport[1] (FAA: O27) | Oakdale, California, United States |
| ODD | YOOD | Oodnadatta Airport[1] | Oodnadatta, South Australia, Australia |
| ODE | EKOD | Hans Christian Andersen Airport | Odense, Denmark |
| ODH | EGVO | RAF Odiham | Odiham, England, United Kingdom |
| ODJ | FEGO | Ouanda Djallé Airport[1] | Ouanda Djallé, Central African Republic |
| ODL | | Cordillo Downs Airport[1] | Cordillo Downs, South Australia, Australia |
| ODM | | Garrett County Airport[1] (FAA: 2G4) | Oakland, Maryland, United States |
| ODN | WBGI | Long Seridan Airport[1] | Long Seridan, Sarawak, Malaysia |
| ODO | UIKB | Bodaybo Airport[1] | Bodaybo, Irkutsk Oblast, Russia |
| ODR | YORV | Ord River Airport[1] | Ord River, Western Australia, Australia |
| ODS | UKOO | Odessa International Airport | Odessa, Ukraine |
| ODW | KOKH | A.J. Eisenberg Airport (FAA: OKH) | Oak Harbor, Washington, United States |
| ODY | VLOS | Oudomsay Airport | Muang Xay (Oudomxai), Laos |
| -OE- |
| OEC | WPOC | Oecusse Airport | Oecussi, East Timor |
| OEL | UUOR | Oryol Yuzhny Airport | Oryol (Orel), Oryol Oblast, Russia |
| OEM | SMPA | Vincent Fayks Airport | Paloemeu, Suriname |
| OEO | KOEO | L.O. Simenstad Municipal Airport | Osceola, Wisconsin, United States |
| OER | ESNO | Örnsköldsvik Airport | Örnsköldsvik, Sweden |
| OES | SAVN | Antoine de Saint Exupéry Airport | San Antonio Oeste, Río Negro, Argentina |
| -OF- |
| OFF | KOFF | Offutt Air Force Base | Omaha, Nebraska, United States |
| OFI | DIOF | Ouango Fitini Airport[1] | Ouango Fitini, Ivory Coast |
| OFJ | BIOF | Ólafsfjörður Airport[1] | Ólafsfjörður, Iceland |
| OFK | KOFK | Norfolk Regional Airport (Karl Stefan Memorial Field) | Norfolk, Nebraska, United States |
| OFU | NSAS | Ofu Airport (FAA: Z08) | Ofu Island, American Samoa |
| -OG- |
| OGA | KOGA | Searle Field | Ogallala, Nebraska, United States |
| OGB | KOGB | Orangeburg Municipal Airport | Orangeburg, South Carolina, United States |
| OGD | KOGD | Ogden-Hinckley Airport | Ogden, Utah, United States |
| OGE | | Ogeramnang Airport[1] | Ogeramnang, Papua New Guinea |
| OGG | PHOG | Kahului Airport | Kahului, Hawaii, United States |
| OGL | SYGO | Ogle Airport | Georgetown, Guyana |
| OGM | | Ustupu-Ogobsucum Airport[1] | Ustupo, Panama |
| OGN | ROYN | Yonaguni Airport | Yonaguni, Yaeyama Islands, Japan |
| OGO | DIAU | Abengourou Airport[1] | Abengourou, Ivory Coast |
| OGR | FTTB | Bongor Airport | Bongor, Chad |
| OGS | KOGS | Ogdensburg International Airport | Ogdensburg, New York, United States |
| OGU | LTCB | Ordu-Giresun Airport | Ordu / Giresun, Turkey |
| OGV | FYNG | Ongava Airstrip[1] | Ongava, Namibia |
| OGX | DAUU | Ain Beida Airport | Ouargla, Algeria |
| OGZ | URMO | Beslan Airport | Vladikavkaz, North Ossetia-Alania, Russia |
| -OH- |
| OHA | NZOH | RNZAF Base Ohakea[1] | Bulls, New Zealand |
| OHB | | Ambohibary Airport[1] | Moramanga, Madagascar |
| OHD | LWOH | Ohrid "St. Paul the Apostle" Airport | Ohrid, Republic of Macedonia |
| OHE | ZYMH | Mohe Gulian Airport | Mohe, Heilongjiang, China |
| OHH | UHSH | Okha Airport (Novostroyka Airport) | Okha, Sakhalin Oblast, Russia |
| OHI | FYOS | Oshakati Airport[1] | Oshakati, Namibia |
| OHO | UHOO | Okhotsk Airport | Okhotsk, Khabarovsk Krai, Russia |
| OHR | EDXY | Wyk auf Föhr Airport[1] | Wyk auf Föhr, Schleswig-Holstein, Germany |
| OHS | OOSH | Sohar Airport[1] | Sohar, Oman |
| OHT | OPKT | PAF Base Kohat | Kohat, Pakistan |
| -OI- |
| OIA | SDOW | Ourilândia do Norte Airport[1] | Ourilândia do Norte, Pará, Brazil |
| OIC | KOIC | Lt. Warren Eaton Airport | Norwich, New York, United States |
| OIM | RJTO | Oshima Airport[1] | Ōshima, Izu Islands, Japan |
| OIR | RJEO | Okushiri Airport | Okushiri, Okushiri Island, Japan |
| OIT | RJFO | Oita Airport | Oita, Kyushu, Japan |
| -OJ- |
| OJC | KOJC | Johnson County Executive Airport | Olathe, Kansas, United States |
| -OK- |
| OKA | ROAH | Naha Airport | Okinawa, Ryukyu Islands, Japan |
| OKB | YORC | Orchid Beach Airport | Fraser Island, Queensland, Australia |
| OKC | KOKC | Will Rogers World Airport | Oklahoma City, Oklahoma, United States |
| OKD | RJCO | Okadama Airport[1] | Sapporo, Hokkaido, Japan |
| OKE | RJKB | Okinoerabu Airport[1] | Okinoerabujima, Amami Islands, Japan |
| OKF | FYOO | Okaukuejo Airport[1] | Okaukuejo, Namibia |
| OKG | | Okoyo Airport[1] | Okoyo, Republic of the Congo |
| OKH | EGXJ | RAF Cottesmore | Oakham, England, United Kingdom |
| OKI | RJNO | Oki Airport[1] | Dogo, Oki Islands, Japan |
| OKJ | RJOB | Okayama Airport | Okayama, Honshu, Japan |
| OKK | KOKK | Kokomo Municipal Airport | Kokomo, Indiana, United States |
| OKL | WAJO | Gunung Bintang Airport | Oksibil, Indonesia |
| OKM | KOKM | Okmulgee Regional Airport | Okmulgee, Oklahoma, United States |
| OKN | FOGQ | Okondja Airport[1] | Okondja, Gabon |
| OKO | RJTY | Yokota Air Base[1] | Fussa, Honshu, Japan |
| OKP | | Oksapmin Airport[1] | Oksapmin, Papua New Guinea |
| OKQ | WAKO | Okaba Airport[1] | Okaba, Indonesia |
| OKR | YYKI | Yorke Island Airport[1] | Yorke Island, Queensland, Australia |
| OKS | KOKS | Garden County Airport | Oshkosh, Nebraska, United States |
| OKT | UWUK | Oktyabrsky Airport | Oktyabrsky, Bashkortostan, Russia |
| OKU | FYMO | Mokuti Lodge Airport[1] | Mokuti Lodge, Namibia |
| OKV | | Okao Airport[1] | Okao, Papua New Guinea |
| OKY | YBOK | Oakey Army Aviation Centre[1] | Oakey, Queensland, Australia |
| -OL- |
| OLA | ENOL | Ørland Airport[1] | Ørland, Norway |
| OLB | LIEO | Olbia Costa Smeralda Airport | Olbia, Sardinia, Italy |
| OLC | SDCG | Senadora Eunice Michiles Airport[1] | São Paulo de Olivença, Amazonas, Brazil |
| OLD | KOLD | Old Town Municipal Airport and Seaplane Base (Dewitt Field) | Old Town, Maine, United States |
| OLE | KOLE | Cattaraugus County-Olean Airport | Olean, New York, United States |
| OLF | KOLF | L. M. Clayton Airport | Wolf Point, Montana, United States |
| OLH | | Old Harbor Airport (FAA: 6R7) | Old Harbor, Alaska, United States |
| OLI | BIRF | Rif Airport[1] | Ólafsvík, Iceland |
| OLJ | NVSZ | Olpoi Airport[1] (North West Santo Airport) | Olpoi, Vanuatu |
| OLK | SGOL | Fuerte Olimpo Airport | Fuerte Olimpo, Paraguay |
| OLL | | Oyo Ollombo Airport | Oyo, Republic of the Congo |
| OLM | KOLM | Olympia Regional Airport | Olympia, Washington, United States |
| OLN | SAVM | Lago Musters Airport[1] | Sarmiento, Chubut, Argentina |
| OLO | LKOL | Olomouc Airport (Neředín Airport) | Olomouc, Czech Republic |
| OLP | YOLD | Olympic Dam Airport[1] | Olympic Dam, South Australia, Australia |
| OLQ | | Olsobip Airport[1] | Olsobip, Papua New Guinea |
| OLR | | Forward Operating Base Salerno | Khost, Afghanistan |
| OLS | KOLS | Nogales International Airport | Nogales, Arizona, United States |
| OLU | KOLU | Columbus Municipal Airport | Columbus, Nebraska, United States |
| OLV | KOLV | Olive Branch Airport | Olive Branch, Mississippi, United States |
| OLX | | Olkiombo Airstrip[1] | Olkiombo, Kenya |
| OLY | KOLY | Olney-Noble Airport | Olney / Noble, Illinois, United States |
| OLZ | UEMO | Olyokminsk Airport | Olyokminsk, Yakutia, Russia |
| -OM- |
| OMA | KOMA | Eppley Airfield | Omaha, Nebraska, United States |
| OMB | FOOH | Omboué Hospital Airport[1] | Omboué, Gabon |
| OMC | RPVO | Ormoc Airport | Ormoc, Philippines |
| OMD | FYOG | Oranjemund Airport[1] | Oranjemund, Namibia |
| OME | PAOM | Nome Airport | Nome, Alaska, United States |
| OMF | OJMF | King Hussein Air Base | Mafraq, Jordan |
| OMG | FYOE | Omega Airport[1] | Omega, Namibia |
| OMH | OITR | Urmia Airport[1] | Urmia (Urūmiyeh), Iran |
| OMI | OIAJ | Omidiyeh Air Base | Omidiyeh, Iran |
| OMJ | RJDU | Ōmura Airport[1] | Nagasaki / Ōmura, Kyushu, Japan |
| OMK | KOMK | Omak Airport | Omak, Washington, United States |
| OML | | Omkalai Airport[1] | Omkalai, Papua New Guinea |
| OMM | OOMX | Marmul Airport[1] | Marmul, Oman |
| OMO | LQMO | Mostar Airport | Mostar, Bosnia and Herzegovina |
| OMR | LROD | Oradea International Airport | Oradea, Romania |
| OMS | UNOO | Omsk Tsentralny Airport | Omsk, Omsk Oblast, Russia |
| OMY | | Thbeng Meanchey Airport[1] (Preah Vinhear Airport) | Phnom Tbeng Meanchey, Cambodia |
| -ON- |
| ONA | KONA | Winona Municipal Airport (Max Conrad Field) | Winona, Minnesota, United States |
| ONB | AYQQ | Ononge Airport[1] | Ononge, Papua New Guinea |
| OND | FYOA | Ondangwa Airport[1] | Ondangwa, Namibia |
| ONE | | Onepusu Airport[1] | Onepusu, Solomon Islands |
| ONG | YMTI | Mornington Island Airport[1] | Mornington Island, Queensland, Australia |
| ONH | | Oneonta Municipal Airport (FAA: N66) | Oneonta, New York, United States |
| ONI | WABD | Moanamani Airport[1] | Moanemani (Moanamani), Indonesia |
| ONJ | RJSR | Odate–Noshiro Airport | Ōdate / Noshiro, Honshu, Japan |
| ONK | UERO | Olenyok Airport | Olenyok, Yakutia, Russia |
| ONL | KONL | O'Neill Municipal Airport (John L. Baker Field) | O'Neill, Nebraska, United States |
| ONM | KONM | Socorro Municipal Airport | Socorro, New Mexico, United States |
| ONO | KONO | Ontario Municipal Airport | Ontario, Oregon, United States |
| ONP | KONP | Newport Municipal Airport | Newport, Oregon, United States |
| ONQ | LTAS | Zonguldak Airport | Zonguldak, Turkey |
| ONR | YMNK | Monkira Airport[1] | Monkira, Queensland, Australia |
| ONS | YORV | Onslow Airport[1] | Onslow, Western Australia, Australia |
| ONT | KONT | Ontario International Airport | Ontario, California, United States |
| ONU | NFOL | Ono-i-Lau Airport[1] | Ono-i-Lau, Fiji |
| ONX | MPEJ | Enrique Adolfo Jiménez Airport | Colón, Panama |
| ONY | KONY | Olney Municipal Airport | Olney, Texas, United States |
| -OO- |
| OOA | KOOA | Oskaloosa Municipal Airport | Oskaloosa, Iowa, United States |
| OOK | PAOO | Toksook Bay Airport | Toksook Bay, Alaska, United States |
| OOL | YBCG | Gold Coast Airport (Coolangatta Airport) | Queensland, Queensland, Australia |
| OOM | YCOM | Cooma–Snowy Mountains Airport[1] | Cooma, New South Wales, Australia |
| OOR | YMOO | Mooraberree Airport[1] | Mooraberree, Queensland, Australia |
| OOT | NGON | Onotoa Airport[1] | Onotoa, Kiribati |
| -OP- |
| OPA | BIKP | Kópasker Airport[1] | Kópasker, Iceland |
| OPB | | Open Bay Airport[1] | Open Bay, Papua New Guinea |
| OPF | KOPF | Miami-Opa Locka Executive Airport | Miami, Florida, United States |
| OPI | YOEN | Oenpelli Airport[1] | Gunbalanya (Oenpelli), Queensland, Australia |
| OPL | KOPL | St. Landry Parish Airport (Ahart Field) | Opelousas, Louisiana, United States |
| OPO | LPPR | Francisco de Sá Carneiro Airport | Porto, Portugal |
| OPS | SWSI | Presidente João Figueiredo Airport | Sinop, Mato Grosso, Brazil |
| OPU | AYBM | Balimo Airport[1] | Balimo, Papua New Guinea |
| OPW | FYOP | Opuwa Airport[1] | Opuwo, Namibia |
| -OR- |
| ORA | SASO | Orán Airport | Orán, Salta, Argentina |
| ORB | ESOE | Örebro Airport | Örebro, Sweden |
| ORC | SKOE | Orocue Airport[1] | Orocué, Colombia |
| ORD | KORD | O'Hare International Airport | Chicago, Illinois, United States |
| ORE | LFOZ | Orléans – Saint-Denis-de-l'Hôtel Airport[1] | Orléans, Centre-Val de Loire, France |
| ORF | KORF | Norfolk International Airport | Norfolk, Virginia, United States |
| ORG | SMZO | Zorg en Hoop Airport | Paramaribo, Suriname |
| ORH | KORH | Worcester Regional Airport | Worcester, Massachusetts, United States |
| ORI | KORI | Port Lions Airport | Port Lions, Alaska, United States |
| ORJ | SYDR | Orinduik Airport | Orinduik, Guyana |
| ORK | EICK | Cork Airport | Cork, Ireland |
| ORL | KORL | Orlando Executive Airport | Orlando, Florida, United States |
| ORM | EGBK | Sywell Aerodrome | Northampton, England, United Kingdom |
| ORN | DAOO | Oran Es Sénia Airport | Oran, Algeria |
| ORO | MHYR | Yoro Airport[1] | Yoro, Honduras |
| ORP | FBOR | Orapa Airport[1] | Orapa, Botswana |
| ORR | YYOR | Yorketown Airport | Yorketown, South Australia, Australia |
| ORS | | Orpheus Island Resort Waterport | Orpheus Island, Queensland, Australia |
| ORT | PAOR | Northway Airport | Northway, Alaska, United States |
| ORU | SLOR | Juan Mendoza Airport | Oruro, Bolivia |
| ORV | PFNO | Robert (Bob) Curtis Memorial Airport (FAA: D76) | Noorvik, Alaska, United States |
| ORW | OPOR | Ormara Airport[1] | Ormara, Pakistan |
| ORX | SNOX | Oriximiná Airport[1] | Oriximiná, Pará, Brazil |
| ORY | LFPO | Orly Airport | Paris, Île-de-France, France |
| ORZ | | Orange Walk Airport[1] | Orange Walk Town, Belize |
| -OS- |
| OSA[1] | | metropolitan area1 | Osaka, Honshu, Italy |
| OSB | | Grand Glaize-Osage Beach Airport (FAA: K15) | Osage Beach, Missouri, United States |
| OSC | KOSC | Oscoda–Wurtsmith Airport | Oscoda, Michigan, United States |
| OSD | ESNZ | Åre Östersund Airport | Östersund, Sweden |
| OSE | | Omora Airport[1] | Omora, Papua New Guinea |
| OSF | UUMO | Ostafyevo International Airport | Moscow / Podolsk, Moscow Oblast, Russia |
| OSG | | Ossima Airport[1] | Ossima, Papua New Guinea |
| OSH | KOSH | Wittman Regional Airport | Oshkosh, Wisconsin, United States |
| OSI | LDOS | Osijek Airport | Osijek, Croatia |
| OSK | ESMO | Oskarshamn Airport | Oskarshamn, Sweden |
| OSL | ENGM | Oslo Airport, Gardermoen | Oslo, Norway |
| OSM | ORBM | Mosul International Airport[1] | Mosul, Iraq |
| OSN | RKSO | Osan Air Base[1] | Osan, South Korea |
| OSO | YOSB | Osborne Mine Airport[1] | Osborne Mine, Queensland, Australia |
| OSR | LKMT | Leoš Janáček Airport Ostrava | Ostrava, Czech Republic |
| OSS | UAFO | Osh Airport | Osh, Kyrgyzstan |
| OST | EBOS | Ostend–Bruges International Airport | Ostend / Bruges, Belgium |
| OSU | KOSU | Ohio State University Airport | Columbus, Ohio, United States |
| OSW | UWOR | Orsk Airport | Orsk, Orenburg Oblast, Russia |
| OSX | KOSX | Kosciusko-Attala County Airport | Kosciusko, Mississippi, United States |
| OSY | ENNM | Namsos Airport, Høknesøra | Namsos, Norway |
| OSZ | EPKZ | Koszalin-Zegrze Pomorskie Airport[1] | Koszalin, Poland |
| -OT- |
| OTA | | Mota Airport[1] | Mota, Ethiopia |
| OTC | FTTL | Bol-Bérim Airport | Bol, Chad |
| OTD | | Contadora Airport | Contadora Island, Panama |
| OTG | KOTG | Worthington Municipal Airport | Worthington, Minnesota, United States |
| OTH | KOTH | Southwest Oregon Regional Airport | North Bend, Oregon, United States |
| OTI | WAMR | Pitu Airport[1] | Morotai Island, Indonesia |
| OTJ | FYOW | Otjiwarongo Airport[1] | Otjiwarongo, Namibia |
| OTK | KTMK | Tillamook Airport[1] (FAA: TMK) | Tillamook, Oregon, United States |
| OTL | GQNB | Boutilimit Airport | Boutilimit, Mauritania |
| OTM | KOTM | Ottumwa Regional Airport | Ottumwa, Iowa, United States |
| OTN | | Ed-Air Airport (FAA: 2IG4) | Oaktown, Indiana, United States |
| OTP | LROP | Henri Coandă International Airport | Bucharest, Romania |
| OTR | MRCC | Coto 47 Airport | Coto 47, Costa Rica |
| OTS | | Anacortes Airport (FAA: 74S) | Anacortes, Washington, United States |
| OTT | SJKB | Andre Maggi Airport[1] | Cotriguaçu, Mato Grosso, Brazil |
| OTU | SKOT | Otú Airport[1] | Remedios, Colombia |
| OTV | AGGQ | Ontong Java Airport[1] | Ontong Java Atoll, Solomon Islands |
| OTY | | Oria Airport[1] | Oria, Papua New Guinea |
| OTZ | PAOT | Ralph Wien Memorial Airport | Kotzebue, Alaska, United States |
| -OU- |
| OUA | DFFD | Ouagadougou Airport | Ouagadougou, Burkina Faso |
| OUD | GMFO | Angads Airport | Oujda, Morocco |
| OUE | FCOU | Ouésso Airport[1] | Ouésso, Republic of the Congo |
| OUG | DFCC | Ouahigouya Airport | Ouahigouya, Burkina Faso |
| OUH | FAOH | Oudtshoorn Airport[1] | Oudtshoorn, South Africa |
| OUK | | Out Skerries Airport[1] | Out Skerries, Scotland, United Kingdom |
| OUL | EFOU | Oulu Airport | Oulu, Finland |
| OUM | | Oum Hadjer Airport | Oum Hadjer, Chad |
| OUN | KOUN | University of Oklahoma Westheimer Airport (Max Westheimer Airport) | Norman, Oklahoma, United States |
| OUR | FKKI | Batouri Airport | Batouri, Cameroon |
| OUS | SDOU | Jornalista Benedito Pimentel–Ourinhos State Airport[1] | Ourinhos, São Paulo, Brazil |
| OUT | FTTS | Bousso Airport | Bousso, Chad |
| OUU | | Ouanga Airport[1] | Ouanga, Gabon |
| OUZ | GQPZ | Tazadit Airport | Zouerate, Mauritania |
| -OV- |
| OVA | FMSL | Bekily Airport[1] | Bekily, Madagascar |
| OVB | UNNT | Tolmachevo Airport | Novosibirsk, Novosibirsk Oblast, Russia |
| OVD | LEAS | Asturias Airport (Oviedo Airport) | Oviedo, Asturias, Spain |
| OVE | KOVE | Oroville Municipal Airport | Oroville, California, United States |
| OVG | FAOB | Air Force Base Overberg[1] | Bredasdorp, South Africa |
| OVL | SCOV | El Tuqui Airport[1] | Ovalle, Chile |
| OVR | SAZF | Olavarría Airport | Olavarría, Buenos Aires, Argentina |
| OVS | USHS | Sovetsky Airport | Sovetsky, Khanty-Mansi Autonomous Okrug, Russia |
| -OW- |
| OWA | KOWA | Owatonna Degner Regional Airport | Owatonna, Minnesota, United States |
| OWB | KOWB | Owensboro–Daviess County Airport | Owensboro, Kentucky, United States |
| OWD | KOWD | Norwood Memorial Airport | Norwood, Massachusetts, United States |
| OWE | | Owendo Airport[1] | Owendo, Gabon |
| OWK | KOWK | Central Maine Airport of Norridgewock | Norridgewock, Maine, United States |
| -OX- |
| OXB | GGOV | Osvaldo Vieira International Airport | Bissau, Guinea-Bissau |
| OXC | KOXC | Waterbury–Oxford Airport | Oxford, Connecticut, United States |
| OXD | KOXD | Miami University Airport | Oxford, Ohio, United States |
| OXF | EGTK | Oxford Airport (London Oxford Airport) | Oxford, England, United Kingdom |
| OXO | | Orientos Airport[1] | Orientos, Queensland, Australia |
| OXR | KOXR | Oxnard Airport | Oxnard, California, United States |
| OXY | YMNY | Morney Airport[1] | Morney, Queensland, Australia |
| -OY- |
| OYA | SATG | Goya Airport[1] | Goya, Corrientes, Argentina |
| OYE | FOGO | Oyem Airport[1] | Oyem, Gabon |
| OYG | | Moyo Airport[1] | Moyo Town, Uganda |
| OYK | SBOI | Oiapoque Airport | Oiapoque, Amapá, Brazil |
| OYL | HKMY | Moyale Airport[1] | Moyale, Kenya |
| OYN | YOUY | Ouyen Airport[1] | Ouyen, Victoria, Australia |
| OYO | SAZH | Tres Arroyos Airport | Tres Arroyos, Buenos Aires, Argentina |
| OYP | SOOG | Saint-Georges-de-l'Oyapock Airport[1] | Saint-Georges-de-l'Oyapock, French Guiana |
| -OZ- |
| OZA | KOZA | Ozona Municipal Airport | Ozona, Texas, United States |
| OZC | RPMO | Labo Airport | Ozamiz, Philippines |
| OZG | GMAZ | Zagora Airport[1] | Zagora, Morocco |
| OZH | UKDE | Zaporizhia International Airport | Zaporizhia, Ukraine |
| OZP | LEMO | Morón Air Base[1] | Morón de la Frontera, Andalusia, Spain |
| OZR | KOZR | Cairns Army Airfield | Fort Rucker / Ozark, Alabama, United States |
| OZZ | GMMZ | Ouarzazate Airport | Ouarzazate, Morocco |