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