| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| OXB (BISSAU OSWALDO VIEIRA INTL) | airport | Guinea-Bissau | 11.89 | -15.65 | 129 | 0 | |
| Ochacaname | city | Guinea-Bissau | 12.07 | -16.23 | 19 | 2093 | |
| Oco | city | Guinea-Bissau | 11.80 | -15.70 | 0 | 7706 | |
| Oco Grande | city | Guinea-Bissau | 11.93 | -15.52 | 13 | 12592 | |
| Oco Maunde | city | Guinea-Bissau | 12.27 | -14.20 | 239 | 7466 | |
| Ocon | city | Cacheu | Guinea-Bissau | 12.15 | -16.32 | 131 | 1111 |
| Ocozinho | city | Guinea-Bissau | 11.95 | -15.52 | 98 | 3451 | |
| Ocó | city | Guinea-Bissau | 12.27 | -14.20 | 239 | 7466 | |
| Ogoiel | city | Guinea-Bissau | 11.55 | -14.67 | 226 | 1422 | |
| Olocunda | city | Guinea-Bissau | 12.62 | -14.08 | 209 | 3131 | |
| Olom | city | Oio | Guinea-Bissau | 12.12 | -15.24 | 52 | 3046 |
| Olossate | city | Oio | Guinea-Bissau | 12.32 | -15.33 | 16 | 3192 |
| Olossato | city | Oio | Guinea-Bissau | 12.32 | -15.33 | 16 | 3192 |
| Oloto | city | Guinea-Bissau | 12.57 | -13.83 | 242 | 1937 | |
| Olucunda | city | Guinea-Bissau | 12.62 | -14.08 | 209 | 3131 | |
| Oma | city | Guinea-Bissau | 12.38 | -14.52 | 29 | 5793 | |
| Omaia | city | Guinea-Bissau | 11.87 | -16.07 | 95 | 3822 | |
| Ome | city | Guinea-Bissau | 11.95 | -15.78 | 26 | 11548 | |
| Ompabe | city | Oio | Guinea-Bissau | 12.16 | -15.58 | 160 | 5476 |
| Ondame | city | Guinea-Bissau | 11.77 | -15.93 | 3 | 7071 | |
| Ondongol | city | Guinea-Bissau | 12.32 | -16.48 | 104 | 2323 | |
| Onga | city | Guinea-Bissau | 12.38 | -14.52 | 29 | 5793 | |
| Ongoro | city | Guinea-Bissau | 12.37 | -15.77 | 141 | 5373 | |
| Ongoré | city | Cacheu | Guinea-Bissau | 12.38 | -15.76 | 183 | 5533 |
| Ongoró | city | Cacheu | Guinea-Bissau | 12.38 | -15.76 | 183 | 5533 |
| Opar | city | Guinea-Bissau | 12.67 | -13.72 | 229 | 2735 | |
| Oquesinho | city | Guinea-Bissau | 11.95 | -15.52 | 98 | 3451 | |
| Orango | city | Guinea-Bissau | 11.35 | -15.37 | 59 | 2707 | |
| Orango Grande | city | Guinea-Bissau | 11.15 | -16.13 | 82 | 1742 | |
| Ore Cajaje | city | Guinea-Bissau | 11.67 | -14.23 | 830 | 2308 | |
| Orebode | city | Guinea-Bissau | 12.63 | -13.88 | 104 | 2630 | |
| Orobode | city | Guinea-Bissau | 12.63 | -13.88 | 104 | 2630 | |
| Orè Capege | city | Guinea-Bissau | 11.67 | -14.23 | 830 | 2308 | |
| Orè Maundè | city | Guinea-Bissau | 12.63 | -13.87 | 216 | 2550 | |
| Ossadú | city | Guinea-Bissau | 11.75 | -15.13 | 39 | 1339 | |
| Ossocone | city | Guinea-Bissau | 11.25 | -16.17 | 0 | 896 | |
| Ossocono | city | Guinea-Bissau | 11.25 | -16.17 | 0 | 896 | |
| Ossor | city | Cacheu | Guinea-Bissau | 12.21 | -16.42 | 68 | 1482 |
| Outra Banda | city | Guinea-Bissau | 12.22 | -15.47 | 141 | 9516 |