International airports, regional fields and GA aerodromes — the places every mission starts and ends.

| Company | Type | Location | Codes |
|---|---|---|---|
| Orniela | aerodrome | South Sudan | — |
| Örnlanda | aerodrome | Sweden | — |
| Örnsköldsvik Airport | international | Sweden | IATA OER · ICAO ESNO |
| Orodara Airport | aerodrome | Burkina Faso | — |
| Orofino Municipal | aerodrome | United States | — |
| Orogrande Airport | aerodrome | United States | — |
| Oropoi Airport | aerodrome | Kenya | — |
| Oropoko Airport | aerodrome | Namibia | — |
| O RO Ranch Private Airstrip | aerodrome | United States | — |
| Ororbia | aerodrome | Spain | — |
| Orote Air Field | military airfield | United States | — |
| Oroville Municipal Airport | international | United States | IATA OVE · ICAO KOVE |
aerodrome 30,878international 8,351military airfield 1,867private airstrip 1,800heliport 555regional 460
United States 15,232Brazil 2,982Australia 2,025Canada 1,765France 1,355Russia 1,265United Kingdom 1,109South Africa 938Germany 879Colombia 835Italy 718Indonesia 681Argentina 621Ukraine 570Papua New Guinea 536China 489Mexico 478Venezuela 468Spain 414India 411Namibia 376Chile 358Congo - Kinshasa 356South Sudan 331Poland 327Czechia 277New Zealand 250Kenya 242Sweden 222Japan 195Philippines 188Norway 179Botswana 151Portugal
Operators claiming an entry can correct facts, add services and certificates, and mark their page verified. Claiming is free — see a company’s page for the claim link.
| Orpheus Island Waterport SPB | international | Australia | IATA ORS · ICAO YOPH |
| Orr Airport | aerodrome | Lakeside, United States | — |
| Orr Field | aerodrome | North Platte, United States | — |
| Orrlanda | aerodrome | Sweden | — |
| Orroroo Airport | aerodrome | Australia | — |
| Orr Ranch Airport | aerodrome | Hay Springs, United States | — |
| Orr Regional Airport | aerodrome | United States | ICAO KORB |
| Orsa Airfield Tallhed | aerodrome | Sweden | ICAO ESNR |
| Orsk Airport | international | Russia | IATA OSW · ICAO UWOR |
| Orson Field | aerodrome | United States | — |
| Ørsta/Volda Airport, Hovden | international | Norway | IATA HOV · ICAO ENOV |
| O.R. Tambo International Airport | international | South Africa | IATA JNB · ICAO FAOR |
| Ortega North | aerodrome | Colombia | — |
| Orthodontic Strip | aerodrome | United States | — |
| Ortman Landing Strip | aerodrome | United States | — |
| Ortner Airport | aerodrome | United States | — |
| Orton Landing Field | aerodrome | United States | — |
| Ortonville Municipal Airport-Martinson Field | aerodrome | United States | ICAO KVVV |
| Orum Aerodrome | aerodrome | Blair, United States | — |
| Orungal | aerodrome | Australia | ICAO YORU |
| Orupgaard Flyveplads | aerodrome | Denmark | — |
| Orutjandja Airport | aerodrome | Namibia | — |
| Oruzgan Airport | international | Afghanistan | IATA URZ |
| Orwig RLA Airport | aerodrome | United States | — |
| Oryx Ranch | aerodrome | South Africa | — |
| Orzhytsia | aerodrome | Ukraine | — |
| Osage City Municipal Airport | aerodrome | United States | — |
| Osage Municipal Airport | aerodrome | United States | — |
| Osaka Itami Airport | international | 豊中市, Japan | IATA ITM · ICAO RJOO |
| Osan Air Base | military airfield | South Korea | IATA OSN · ICAO RKSO |
| Osborn Airfield | aerodrome | Groveland, United States | — |
| Osborne Airport | aerodrome | United States | — |
| Osborne Mine Airport | international | Australia | IATA OSO · ICAO YOSB |
| Osborne Municipal Airport | aerodrome | United States | — |
| Óscar Machado Zuloaga International Airport | aerodrome | Venezuela | ICAO SVCS |
| Osceola Municipal Airport | aerodrome | Osceola, United States | — |
| Osceola Municipal Airport | aerodrome | United States | — |
| Osceola Sheriff's Office Bronson Highway Heliport | aerodrome | United States | — |