- Oskido -- Osman
- Osman -- Osmosis (New Age)
- Osm'oz -- Ossian
- Ossian Dox -- Östen Warnerbring
- Oster Project -- Osuna
- Osunlade -- Osvaldo Norton Orquestra
- Osvaldo Paese -- Oswaldo Borda
- Oswaldo Cruz -- O.T. Quartet
- Ot. To 777 -- Otep
- Otesanek -- Other Kids
- Other Kind -- Otherside
- Otherview -- Otis Finch
- Otis Forrest -- Otis & Shug
- Otis & Shug -- OTN
- oto -- Otra Vision
- otracosa -- Otter Petter
- Otter Trail -- Otto Fries
- Otto & George -- Otto Orlandi
- Otto Pasetti -- Ottokar Novacek
- Ottoman -- Oubys
- Ouch! -- Oulaya
- $oulcat -- Oun
- Oun P -- Our God
- Our God Weeps -- Our Souls
- Our Starblazers -- Oustaaz
- Out -- Out of Luck