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