| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| O-ri | city | Korea, Republic of (South) | 36.23 | 127.31 | 830 | 377883 | |
| Oaeo-ri | city | Korea, Republic of (South) | 35.77 | 127.50 | 1669 | 4659 | |
| Obi-ri | city | Korea, Republic of (South) | 34.92 | 128.62 | 150 | 54674 | |
| Och'i | city | Korea, Republic of (South) | 34.50 | 127.32 | 62 | 10809 | |
| Och'on | city | Korea, Republic of (South) | 34.92 | 127.50 | 13 | 85187 | |
| Och'on | city | Korea, Republic of (South) | 34.73 | 127.58 | 183 | 42883 | |
| Och'on-dong | city | Korea, Republic of (South) | 34.92 | 127.50 | 13 | 85187 | |
| Och'on-ni | city | Korea, Republic of (South) | 34.92 | 127.50 | 13 | 85187 | |
| Ochon | city | Korea, Republic of (South) | 38.08 | 126.88 | 285 | 10159 | |
| Och’i | city | Korea, Republic of (South) | 34.50 | 127.32 | 62 | 10809 | |
| Och’ŏn | city | Korea, Republic of (South) | 34.92 | 127.50 | 13 | 85187 | |
| Och’ŏn | city | Korea, Republic of (South) | 34.73 | 127.58 | 183 | 42883 | |
| Och’ŏn-dong | city | Korea, Republic of (South) | 34.92 | 127.50 | 13 | 85187 | |
| Och’ŏn-ni | city | Korea, Republic of (South) | 34.92 | 127.50 | 13 | 85187 | |
| Odo | city | Korea, Republic of (South) | 34.72 | 127.38 | 0 | 7514 | |
| Odo-ri | city | Korea, Republic of (South) | 34.72 | 127.38 | 0 | 7514 | |
| Odong | city | Korea, Republic of (South) | 36.23 | 127.31 | 830 | 377883 | |
| Oedok | city | Korea, Republic of (South) | 35.02 | 126.38 | 26 | 4131 | |
| Oegu | city | Korea, Republic of (South) | 35.12 | 127.45 | 403 | 10802 | |
| Oegu-ri | city | Korea, Republic of (South) | 35.12 | 127.45 | 403 | 10802 | |
| Oegum | city | Korea, Republic of (South) | 34.98 | 127.72 | 13 | 48417 | |
| Oegwangch'on | city | Korea, Republic of (South) | 35.07 | 127.23 | 272 | 10541 | |
| Oegwangch’ŏn | city | Korea, Republic of (South) | 35.07 | 127.23 | 272 | 10541 | |
| Oehwa | city | Korea, Republic of (South) | 35.98 | 126.97 | 6 | 102254 | |
| Oehwa-ri | city | Korea, Republic of (South) | 35.98 | 126.97 | 6 | 102254 | |
| Oehwang | city | Korea, Republic of (South) | 35.87 | 126.93 | 9 | 44942 | |
| Oehwang-ni | city | Korea, Republic of (South) | 35.87 | 126.93 | 9 | 44942 | |
| Oehwangsan | city | Korea, Republic of (South) | 35.87 | 126.93 | 9 | 44942 | |
| Oehyonhwa | city | Korea, Republic of (South) | 35.03 | 126.43 | 62 | 6529 | |
| Oejin | city | Korea, Republic of (South) | 34.87 | 127.60 | 0 | 40710 | |
| Oejungsan | city | Korea, Republic of (South) | 35.62 | 127.72 | 1991 | 6705 | |
| Oenam-ni | city | Korea, Republic of (South) | 35.22 | 126.37 | 3 | 11230 | |
| Oeoch'on | city | Korea, Republic of (South) | 35.77 | 127.50 | 1669 | 4659 | |
| Oeoch’on | city | Korea, Republic of (South) | 35.77 | 127.50 | 1669 | 4659 | |
| Oesin-ni | city | Korea, Republic of (South) | 35.67 | 126.92 | 16 | 17155 | |
| Oesong | city | Korea, Republic of (South) | 34.98 | 127.27 | 830 | 11920 | |
| Ogang-ni | city | Korea, Republic of (South) | 35.03 | 126.75 | 16 | 88781 | |
| Ogong-ni | city | Korea, Republic of (South) | 35.70 | 126.80 | 22 | 18248 | |
| Ojae | city | Korea, Republic of (South) | 34.50 | 127.32 | 62 | 10809 | |
| Ok-tong | city | Korea, Republic of (South) | 34.92 | 127.92 | 101 | 7180 | |
| Ok-tong | city | Korea, Republic of (South) | 34.87 | 128.55 | 1069 | 32469 | |
| Ok-tong | city | Korea, Republic of (South) | 35.08 | 126.58 | 52 | 12109 | |
| Okch'ae | city | Korea, Republic of (South) | 34.97 | 127.20 | 830 | 9922 | |
| Okcha | city | Korea, Republic of (South) | 34.97 | 127.20 | 830 | 9922 | |
| Okch’ae | city | Korea, Republic of (South) | 34.97 | 127.20 | 830 | 9922 | |
| Okp'o | city | Korea, Republic of (South) | 34.70 | 128.62 | 0 | 6457 | |
| Okp’o | city | Korea, Republic of (South) | 34.70 | 128.62 | 0 | 6457 | |
| Oksŭl-li | city | Korea, Republic of (South) | 35.17 | 126.37 | 0 | 7251 | |
| Olmok | city | Korea, Republic of (South) | 35.98 | 127.62 | 1669 | 5755 | |
| Omae | city | Korea, Republic of (South) | 35.18 | 126.90 | 118 | 394122 | |
| Oman-ni | city | Korea, Republic of (South) | 34.80 | 127.73 | 269 | 72926 | |
| On'go | city | Korea, Republic of (South) | 35.28 | 126.50 | 75 | 28716 | |
| On'go-ri | city | Korea, Republic of (South) | 35.28 | 126.50 | 75 | 28716 | |
| Ondolgae | city | Korea, Republic of (South) | 34.88 | 127.73 | 0 | 19146 | |
| Ondolp'o | city | Korea, Republic of (South) | 34.88 | 127.73 | 0 | 19146 | |
| Ondolp’o | city | Korea, Republic of (South) | 34.88 | 127.73 | 0 | 19146 | |
| Ondong | city | Korea, Republic of (South) | 34.88 | 127.73 | 0 | 19146 | |
| Ong-dong | city | Korea, Republic of (South) | 35.53 | 126.90 | 357 | 46394 | |
| Ongam-ni | city | Korea, Republic of (South) | 34.78 | 127.38 | 3 | 8830 | |
| Ongmyong | city | Korea, Republic of (South) | 34.87 | 128.73 | 0 | 32126 | |
| Ongmyonggol | city | Korea, Republic of (South) | 34.87 | 128.73 | 0 | 32126 | |
| Ongmyŏng-ni | city | Korea, Republic of (South) | 34.87 | 128.73 | 0 | 32126 | |
| Ongp'o | city | Korea, Republic of (South) | 34.73 | 127.25 | 0 | 4933 | |
| Ongp’o | city | Korea, Republic of (South) | 34.73 | 127.25 | 0 | 4933 | |
| Onp'o | city | Korea, Republic of (South) | 35.60 | 126.48 | 9 | 4930 | |
| Onp'o-ri | city | Korea, Republic of (South) | 35.60 | 126.48 | 9 | 4930 | |
| Onp’o-ri | city | Korea, Republic of (South) | 35.60 | 126.48 | 9 | 4930 | |
| Onsekiho | city | Korea, Republic of (South) | 34.88 | 127.73 | 0 | 19146 | |
| Ontoruho | city | Korea, Republic of (South) | 34.88 | 127.73 | 0 | 19146 | |
| Op'o | city | Korea, Republic of (South) | 34.70 | 128.62 | 0 | 6457 | |
| Optong | city | Korea, Republic of (South) | 34.97 | 127.50 | 830 | 84738 | |
| Optong-ni | city | Korea, Republic of (South) | 34.97 | 127.50 | 830 | 84738 | |
| Op’o | city | Korea, Republic of (South) | 34.70 | 128.62 | 0 | 6457 | |
| Oram-ni | city | Korea, Republic of (South) | 35.10 | 126.32 | 52 | 4078 | |
| Ore-ch'on | city | Korea, Republic of (South) | 35.27 | 127.08 | 830 | 8201 | |
| Ore-ch’on | city | Korea, Republic of (South) | 35.27 | 127.08 | 830 | 8201 | |
| Oridong | city | Korea, Republic of (South) | 38.00 | 126.84 | 157 | 9555 | |
| Orim | city | Korea, Republic of (South) | 34.77 | 127.72 | 203 | 74539 | |
| Orim-ni | city | Korea, Republic of (South) | 34.77 | 127.72 | 203 | 74539 | |
| Orye-ch'on | city | Korea, Republic of (South) | 35.27 | 127.08 | 830 | 8201 | |
| Orye-ch’on | city | Korea, Republic of (South) | 35.27 | 127.08 | 830 | 8201 | |
| Oryong-dong | city | Korea, Republic of (South) | 35.05 | 126.25 | 26 | 38440 | |
| Oryu | city | Korea, Republic of (South) | 34.97 | 127.68 | 830 | 55055 | |
| Oryu-ch'on | city | Korea, Republic of (South) | 35.10 | 126.32 | 52 | 4078 | |
| Oryu-ch’on | city | Korea, Republic of (South) | 35.10 | 126.32 | 52 | 4078 | |
| Oryu-dong | city | Korea, Republic of (South) | 35.10 | 126.32 | 52 | 4078 | |
| Oryu-ri | city | Korea, Republic of (South) | 35.05 | 126.35 | 29 | 2947 | |
| Oryuch'on | city | Korea, Republic of (South) | 34.43 | 127.22 | 0 | 4093 | |
| Oryuch’on | city | Korea, Republic of (South) | 34.43 | 127.22 | 0 | 4093 | |
| Orŭng-ni | city | Korea, Republic of (South) | 35.18 | 127.37 | 830 | 8367 | |
| Osan | city | Korea, Republic of (South) | 35.07 | 127.28 | 288 | 10532 | |
| Osan | city | Korea, Republic of (South) | 35.93 | 126.92 | 6 | 89679 | |
| Osan-ni | city | Korea, Republic of (South) | 35.07 | 127.28 | 288 | 10532 | |
| Osan-ni | city | Korea, Republic of (South) | 35.93 | 126.92 | 6 | 89679 | |
| Osan-ni | city | Korea, Republic of (South) | 35.52 | 126.67 | 26 | 8452 | |
| Osan-ri | city | Korea, Republic of (South) | 35.93 | 126.92 | 6 | 89679 | |
| Osom | city | Korea, Republic of (South) | 34.72 | 127.38 | 0 | 7514 | |
| Osong | city | Korea, Republic of (South) | 34.82 | 128.60 | 55 | 25454 | |
| Osong-ni | city | Korea, Republic of (South) | 34.82 | 128.60 | 55 | 25454 | |
| Ou | city | Korea, Republic of (South) | 35.97 | 127.18 | 131 | 13870 | |
| Oun-dong | city | Korea, Republic of (South) | 35.05 | 126.37 | 3 | 2748 | |
| Oyong-dong | city | Korea, Republic of (South) | 35.05 | 126.25 | 26 | 38440 | |
| Oyu-dong | city | Korea, Republic of (South) | 35.10 | 126.32 | 52 | 4078 |