| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
| Oboen | city | State of Chuuk | Federated States of Micronesia | 7.3336111 | 151.8366667 | 3 | 3575 |
| Olip | city | State of Chuuk | Federated States of Micronesia | 7.3316667 | 151.6066667 | 1249 | 4212 |
| Onip | city | State of Chuuk | Federated States of Micronesia | 7.3316667 | 151.6066667 | 1249 | 4212 |
| Onip | city | State of Chuuk | Federated States of Micronesia | 7.3766667 | 151.7313889 | 0 | 906 |
| Onongoch | city | State of Chuuk | Federated States of Micronesia | 7.35 | 151.8333333 | 3 | 2646 |
| Onongot | city | State of Chuuk | Federated States of Micronesia | 7.35 | 151.8333333 | 3 | 2646 |
| Opun | city | State of Chuuk | Federated States of Micronesia | 7.3525 | 151.7816667 | 0 | 1494 |
| Oror en Fein | city | State of Chuuk | Federated States of Micronesia | 7.3475 | 151.8341667 | 3 | 3575 |