- 1 Oceana
- 2 Olivia Dean
- 3 Olivia Addams
- 4 Oly
- 5 Odessa
- 6 Olivia Herdt
- 7 Otilia
- 8 One-T
- 9 Orianthi
- 10 Oceanside
- 11 Oh Susanna
- 12 Orkid
- 13 Oh Land
- 14 Olivia Belli
- 15 OR3O
- 16 Olga Lounova
- 17 Olivera
- 18 Ony
- 19 Origa
- 20 Otis McDonald
- 21 OSTON
- 22 ooxygen
- 23 Odetta
- 24 Ornella Vanoni
- 25 Okay Kaya
- 26 Olivia Broadfield
- 27 Olivia Ruiz
- 28 Ofelia
- 29 Olivia Newton-John
- 30 Olivia O'Brien