| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Obama | city | Nagasaki | Japan | 32.72 | 130.21 | 344 | 15909 |
| Obita | city | Nagasaki | Japan | 32.82 | 129.88 | 275 | 140958 |
| Ochi | city | Nagasaki | Japan | 34.64 | 129.39 | 157 | 2551 |
| Odacho | city | Nagasaki | Japan | 33.19 | 129.41 | 249 | 4484 |
| Odao | city | Nagasaki | Japan | 32.73 | 129.85 | 3 | 154771 |
| Oe | city | Nagasaki | Japan | 32.64 | 130.26 | 3 | 15843 |
| Ogakura | city | Nagasaki | Japan | 32.82 | 130.05 | 328 | 74185 |
| Ogatacho | city | Nagasaki | Japan | 33.18 | 129.65 | 3 | 48880 |
| Ogawa | city | Nagasaki | Japan | 33.38 | 129.56 | 3 | 11679 |
| Ogawa | city | Nagasaki | Japan | 32.62 | 128.68 | 298 | 3360 |
| Ogawachicho | city | Nagasaki | Japan | 33.23 | 129.70 | 278 | 66080 |
| Ogawago | city | Nagasaki | Japan | 32.62 | 128.68 | 298 | 3360 |
| Oguri | city | Nagasaki | Japan | 33.07 | 129.73 | 0 | 33530 |
| Ogushigo | city | Nagasaki | Japan | 33.06 | 129.84 | 95 | 38618 |
| Ohama | city | Nagasaki | Japan | 32.65 | 128.81 | 85 | 13769 |
| Ohazu | city | Nagasaki | Japan | 33.27 | 129.75 | 1049 | 32729 |
| Oishi | city | Nagasaki | Japan | 32.88 | 129.78 | 104 | 47407 |
| Oishi | city | Nagasaki | Japan | 33.03 | 129.74 | 3 | 20364 |
| Okawara | city | Nagasaki | Japan | 32.98 | 129.13 | 291 | 7765 |
| Okishinmachi | city | Nagasaki | Japan | 33.15 | 129.75 | 39 | 85450 |
| Okubo | city | Nagasaki | Japan | 34.47 | 129.33 | 259 | 3819 |
| Okuno | city | Nagasaki | Japan | 33.03 | 129.70 | 830 | 14488 |
| Okuura | city | Nagasaki | Japan | 32.74 | 128.82 | 147 | 8827 |
| Okuura | city | Nagasaki | Japan | 32.93 | 129.68 | 830 | 8231 |
| Okuyamacho | city | Nagasaki | Japan | 33.08 | 129.83 | 265 | 64983 |
| Okūra | city | Nagasaki | Japan | 32.93 | 129.68 | 830 | 8231 |
| Omadaka | city | Nagasaki | Japan | 33.08 | 129.67 | 26 | 11623 |
| Omodaka | city | Nagasaki | Japan | 33.08 | 129.67 | 26 | 11623 |
| Omotaka | city | Nagasaki | Japan | 33.08 | 129.67 | 26 | 11623 |
| Omura | city | Nagasaki | Japan | 32.92 | 129.95 | 65 | 61236 |
| Onikigō | city | Nagasaki | Japan | 33.12 | 129.92 | 935 | 27266 |
| Onocho | city | Nagasaki | Japan | 33.21 | 129.73 | 390 | 89654 |
| Onoe | city | Nagasaki | Japan | 32.68 | 129.80 | 3 | 50084 |
| Onoue | city | Nagasaki | Japan | 32.68 | 129.80 | 3 | 50084 |
| Onoue-machi | city | Nagasaki | Japan | 32.68 | 129.80 | 3 | 50084 |
| Onouecho | city | Nagasaki | Japan | 32.68 | 129.80 | 3 | 50084 |
| Oomi | city | Nagasaki | Japan | 34.47 | 129.28 | 160 | 1891 |
| Orishikisegō | city | Nagasaki | Japan | 33.14 | 129.90 | 242 | 34150 |
| Osaki | city | Nagasaki | Japan | 34.31 | 129.22 | 137 | 3532 |
| Osaki | city | Nagasaki | Japan | 32.68 | 130.35 | 3 | 16349 |
| Osashicho | city | Nagasaki | Japan | 33.23 | 129.41 | 318 | 6764 |
| Oshika | city | Nagasaki | Japan | 34.52 | 129.43 | 3 | 2602 |
| Oshimacho | city | Nagasaki | Japan | 33.05 | 129.61 | 301 | 7268 |
| Oshimamura-azuchi-kawachi | city | Nagasaki | Japan | 33.48 | 129.53 | 269 | 1792 |
| Oshimamura-azuchi-toda | city | Nagasaki | Japan | 33.49 | 129.52 | 3 | 1755 |
| Ota | city | Nagasaki | Japan | 32.95 | 129.15 | 0 | 5265 |
| Otawa | city | Nagasaki | Japan | 33.04 | 129.67 | 830 | 11466 |
| Oura | city | Nagasaki | Japan | 32.88 | 129.08 | 164 | 5838 |
| Oura | city | Nagasaki | Japan | 34.67 | 129.43 | 246 | 2728 |
| Oya | city | Nagasaki | Japan | 32.62 | 130.20 | 167 | 21711 |
| Oyama | city | Nagasaki | Japan | 33.38 | 129.83 | 173 | 8602 |
| Oyo | city | Nagasaki | Japan | 32.62 | 130.20 | 167 | 21711 |
| Ozaki | city | Nagasaki | Japan | 34.31 | 129.22 | 137 | 3532 |