World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Oskarshamn | SEOSK | Sweden |
| Oslo | NOOSL | Norway |
| Osloss | DEOSL | Germany |
| Osmussaare Sadam | EEOSM | Estonia |
| Osnabrück | DEOSN | Germany |
| Osnes - Vindafjord | NOOSE | Norway |
| Oso | NGOSO | Nigeria |
| Osoe | JPOSE | Japan |
| Osorno | CLZOS | Chile |
| Ospakseyri | ISOSP | Iceland |