World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Oberhausen | DEOBE | Germany |
| Oberhausen an der Nahe | DEOAN | Germany |
| Oberkotzau | DEOKY | Germany |
| Oberlin | USXOR | United States of America (the) |
| Oberneukirchen | ATOBU | Austria |
| Oberried am Brienzersee | CHODB | Switzerland |
| Oberthal | DEDEO | Germany |
| Oberwesel | DEOEE | Germany |
| Oberwinter | DEOWT | Germany |
| Obi Island | IDOBI | Indonesia |