| Song Title | Artist | Genre |
|---|---|---|
| OK | Robin Schulz f./James Blunt | Powerset 2 |
| OMG | Usher f./Will.I.Am | Top 40 |
| OMYGOD! | Kate Nash | Top 40 |
| OOOUUU | Young M.A. | Hip-Hop |
| OPM | Katrina | |
| OTL | Little Hurricane | Rock |
| OTW | DJ Luke Nasty f./2 Chainz | Hip-Hop |
| OWM | GITCHII | Dance |
| Oasis | A Great Big World | Pop |
| Oath | Cher Lloyd f./Becky G | Pop/Hip-Hop |
