| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Обор | city | Chitinskaya Oblast' | Russia | 50.98 | 108.55 | 2322 | 0 |
| Обшивково | city | Chitinskaya Oblast' | Russia | 50.57 | 110.53 | 3087 | 0 |
| Овцеводческая Товарная Ферма | city | Chitinskaya Oblast' | Russia | 51.45 | 113.99 | 2217 | 298 |
| Овцеводческая Товарная Ферма Малая Тура | city | Chitinskaya Oblast' | Russia | 51.45 | 113.99 | 2217 | 298 |
| Озёрное | city | Chitinskaya Oblast' | Russia | 52.80 | 117.57 | 2365 | 281 |
| Окоронда | city | Chitinskaya Oblast' | Russia | 53.17 | 118.15 | 1929 | 298 |
| Октябрьский | city | Chitinskaya Oblast' | Russia | 50.08 | 118.18 | 2345 | 2679 |
| Олдонда | city | Chitinskaya Oblast' | Russia | 50.88 | 116.93 | 2916 | 0 |
| Олекан | city | Chitinskaya Oblast' | Russia | 52.37 | 116.07 | 1801 | 447 |
| Оленгуй | city | Chitinskaya Oblast' | Russia | 51.31 | 113.41 | 2352 | 298 |
| Олинск | city | Chitinskaya Oblast' | Russia | 52.40 | 116.22 | 1650 | 447 |
| Оловянная | city | Chitinskaya Oblast' | Russia | 50.95 | 115.57 | 1929 | 715 |
| Олочи | city | Chitinskaya Oblast' | Russia | 51.35 | 119.92 | 1601 | 244 |
| Олукучаг | city | Chitinskaya Oblast' | Russia | 49.57 | 111.78 | 3133 | 149 |
| Оморой | city | Chitinskaya Oblast' | Russia | 52.97 | 118.97 | 1364 | 149 |
| Онгонцон | city | Chitinskaya Oblast' | Russia | 50.25 | 112.98 | 2975 | 149 |
| Онкоёк | city | Chitinskaya Oblast' | Russia | 50.35 | 113.03 | 2631 | 149 |
| Онон-Борзя | city | Chitinskaya Oblast' | Russia | 51.07 | 117.33 | 2867 | 149 |
| Ононское | city | Chitinskaya Oblast' | Russia | 50.98 | 115.57 | 1958 | 618 |
| Онохово | city | Chitinskaya Oblast' | Russia | 51.62 | 116.80 | 2257 | 149 |
| Онохой | city | Chitinskaya Oblast' | Russia | 51.33 | 119.85 | 1653 | 190 |
| Орловский | city | Chitinskaya Oblast' | Russia | 51.65 | 114.33 | 2112 | 298 |
| Орой | city | Chitinskaya Oblast' | Russia | 50.17 | 113.73 | 2808 | 149 |
| Орсук | city | Chitinskaya Oblast' | Russia | 50.95 | 108.82 | 2224 | 0 |
| Осиновка | city | Chitinskaya Oblast' | Russia | 50.57 | 109.45 | 2749 | 0 |
| Островки | city | Chitinskaya Oblast' | Russia | 52.07 | 115.98 | 2155 | 745 |
| Очунонда | city | Chitinskaya Oblast' | Russia | 53.17 | 117.47 | 2568 | 298 |