World Sea Ports
| Port Name | Port Code | Country Name |
|---|---|---|
| Okiuranishi | JPOKS | Japan |
| Okogi | JPOKG | Japan |
| Okono | NGOKN | Nigeria |
| Okpo/Geoje | KROKP | Korea, Republic of |
| Okrika | NGOKR | Nigeria |
| Okruzhnoe | RUOKZ | Russian Federation (the) |
| Oksnes | NOOKS | Norway |
| Oktyabr'skiy | RUOKT | Russian Federation (the) |
| Oktyabrskoye | RUOYE | Russian Federation (the) |
| Oku | JPOKU | Japan |