Airports
| Airport Name | Airport Code | Country |
|---|---|---|
| Ord River | ODR | Australia |
| Orientos | OXO | Australia |
| Oenpelli | OPI | Australia |
| Off Line Point | WGZ | Australia |
| Onslow | ONS | Australia |
| Oakey | OKY | Australia |
| Oodnadatta | ODD | Australia |
| Oban | OBA | Australia |
| Off Line Point | WGF | Bahrain |
| Osmani International | ZYL | Bangladesh |
| Oostmalle | OBL | Belgium |
| Ostend/Bruges International Airport | OST | Belgium |
| Orange Walk | ORZ | Belize |
| Oruro | ORU | Bolivia |
| Orapa | ORP | Botswana |
| Oriximina | ORX | Brazil |
| Obidos | OBI | Brazil |
| Oiapoque | OYK | Brazil |
| Ourinhos | OUS | Brazil |
| Ourilandia | OIA | Brazil |