World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Oss | NLOSS | Netherlands |
| Ossenberg | DEOSB | Germany |
| Ossenzijl | NLOZL | Netherlands |
| Ostend (Oostende) | BEOST | Belgium |
| Österby | EEOST | Estonia |
| Ostermoor | DEOSR | Germany |
| Osterøy | NOOST | Norway |
| Osterrönfeld | DETRD | Germany |
| Osterville | USOV3 | United States of America (the) |
| Osterwald | DETER | Germany |