World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Oia Kyklades | GROIK | Greece |
| Oigny-en-Valois | FROYI | France |
| Oirschot | NLOIH | Netherlands |
| Oiso | JPOIS | Japan |
| Oisquercq | BEOQC | Belgium |
| Oita | JPOIT | Japan |
| Oiu | EEOIU | Estonia |
| Ojdula | ROOJD | Romania |
| Ojika | JPOJI | Japan |
| Ojoya | JPOYA | Japan |