| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| O-iwa | city | Chuuk | Federated States of Micronesia | 7.45 | 151.88 | 0 | 8647 |
| Oa | city | Pohnpei | Federated States of Micronesia | 6.92 | 158.31 | 0 | 5627 |
| Oarmoar | city | Pohnpei | Federated States of Micronesia | 6.94 | 158.17 | 830 | 9786 |
| Oaumoar | city | Pohnpei | Federated States of Micronesia | 6.94 | 158.17 | 830 | 9786 |
| Oaunoar | city | Pohnpei | Federated States of Micronesia | 6.94 | 158.17 | 830 | 9786 |
| Oboen | city | Chuuk | Federated States of Micronesia | 7.33 | 151.84 | 3 | 13949 |
| Ohwa | city | Pohnpei | Federated States of Micronesia | 6.92 | 158.31 | 0 | 5627 |
| Okat | city | Kosrae | Federated States of Micronesia | 5.33 | 162.97 | 961 | 7069 |
| Okau | city | Yap | Federated States of Micronesia | 9.53 | 138.10 | 344 | 7286 |
| Olip | city | Chuuk | Federated States of Micronesia | 7.33 | 151.61 | 1249 | 24668 |
| Omin | city | Yap | Federated States of Micronesia | 9.60 | 138.15 | 131 | 3971 |
| Omin | city | Yap | Federated States of Micronesia | 9.60 | 138.17 | 82 | 3809 |
| Onean | city | Pohnpei | Federated States of Micronesia | 6.82 | 158.28 | 85 | 8229 |
| Onip | city | Chuuk | Federated States of Micronesia | 7.38 | 151.73 | 0 | 4384 |
| Onip | city | Chuuk | Federated States of Micronesia | 7.33 | 151.61 | 1249 | 24668 |
| Onongoch | city | Chuuk | Federated States of Micronesia | 7.35 | 151.83 | 3 | 12935 |
| Onongot | city | Chuuk | Federated States of Micronesia | 7.35 | 151.83 | 3 | 12935 |
| Opun | city | Chuuk | Federated States of Micronesia | 7.35 | 151.78 | 0 | 6000 |
| Or | city | Chuuk | Federated States of Micronesia | 7.45 | 151.90 | 0 | 5052 |
| Orila | city | Yap | Federated States of Micronesia | 9.58 | 138.16 | 6 | 6883 |
| Orile | city | Yap | Federated States of Micronesia | 9.58 | 138.16 | 6 | 6883 |
| Orira | city | Yap | Federated States of Micronesia | 9.58 | 138.16 | 6 | 6883 |
| Oror en Fein | city | Chuuk | Federated States of Micronesia | 7.35 | 151.83 | 3 | 13886 |
| Orowoo | city | Yap | Federated States of Micronesia | 9.51 | 138.13 | 0 | 7466 |
| Oumoar | city | Pohnpei | Federated States of Micronesia | 6.94 | 158.17 | 830 | 9786 |