World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Olpenitz | DEOLP | Germany |
| Oltenita | ROOLT | Romania |
| Olton | USQOT | United States of America (the) |
| Oluvil | LKOLU | Sri Lanka |
| Olviia | UAOCT | Ukraine |
| Olya | RUOYA | Russian Federation (the) |
| Olympia | USOLM | United States of America (the) |
| Olyphant | USQOA | United States of America (the) |
| Oma | JPOAX | Japan |
| Omachi | JPOMC | Japan |