- 1 Olivia Rodrigo
- 2 Olivia Dean
- 3 Olivera
- 4 OR3O
- 5 Otilia
- 6 Oonagh
- 7 Origa
- 8 Orianthi
- 9 Olivia Newton-John
- 10 ooxygen
- 11 Olivia Broadfield
- 12 Oh Susanna
- 13 Orenda Fink
- 14 Oh Land
- 15 Olivia Theresa Longott
- 16 Olivia Henken
- 17 Ornella Vanoni
- 18 Odetta
- 19 oleta adams
- 20 Omara Portuondo
- 21 Ophélie Winter
- 22 Orli Shaham
- 23 Oumou Sangaré
- 24 Olia Tira
- 25 OK Sweetheart
- 26 Olivia Kay
- 27 Orelia Has Orchestra
- 28 Olivia Holt
- 29 Oana Radu
- 30 One T