| Bulat Okudzhava | SoundtrackBard music | 5 |
| Emily Osment | Pop | 1 |
| Tom Odell | Bard musicPopDance musicElectronic music | 5 |
| Gilbert O'Sullivan | Pop | 3 |
| Tony Orlando and Dawn | Pop | 1 |
| Stars On 45 | Dance music | 1 |
| Billy Ocean | PopSoul | 4 |
| Michail Obychayko | Waltz | 1 |
| Music of Wales | Folk | 14 |
| Dasha Oganezova | Children's song | 2 |
| Vitaly Okorokov | ChansonPop | 7 |
| Olya Polyakova | Pop | 3 |
