World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Ooigem | BEOOG | Belgium |
| Ooltewah | USZOW | United States of America (the) |
| Ooltgensplaat | NLOGP | Netherlands |
| Oortkaten | DEOTK | Germany |
| Oosterhout | NLOOS | Netherlands |
| Oosterlittens | NLOLS | Netherlands |
| Oosterlo | BEOTL | Belgium |
| Oostermeer | NLOME | Netherlands |
| Oosthem | NLOHM | Netherlands |
| Oosthuizen | NLOHZ | Netherlands |