- O
- OO
- OO
- OOak
- OakObe
- ObeObs
- ObsOce
- OceOCS
- OCSOda
- OdaODE
- ODEODU
- ODUOfe
- OfeOfr
- oftOh
- OhOhj
- OHKOji
- OJMOke
- OkeOla
- OlaOld
- OldOle
- OleOli
- OliOll
- OllOm
- OmOme
- OmeOmn
- OmnOnc
- One
- OneOne
- OneOni
- ONIOno
- OnoOon
- OonOpe
- OpeOpt
- Ora
- OraOrc
- OrcOrd
- OrdOrg
- OrhOri
- OriOrm
- OrmOrq
- OrqOrt
- OrtOsb
- OsbOsh
- OshOss
- OssOTF
- OtgOtt
- OttOue
- OueOut
- OutOut
- OutOut
- OutOve
- OveOwe
- OweOwn
- OwsOza
- OzaOZZ
- Ono, Yoko feat. Sparks
- Ono, Yoko feat. Tenaglia, Danny
- Ono, Yoko Plastic Ono Band
- Ono, Yoko/IMA
- Onoe Caponoe
- onoken
- Onokio
- Önol, Onat
- Onono, Ben
- Onorata
- ONR.
- Onra (French producer/beatmaker Arnaud Bernard)
- Onra feat. B, Reggie
- Onrust (Dutch 2000s black metal)
- Onrust (Belgian post-metal band)
- Onsa Media (a group of musicians, who records covers mainly and sometimes original songs and parodies also)
- Onsind (acoustic pop punk band)
- Onslaught (UK punk/thrash/speed metal band)
- Onslow (Alternative rock band)
- Ontaneda, Sara
- ontologics
- Ontuak
- Onuabuobi, Victor (Nigerian gospel singer)
- Onuka
- Onuki, Taeko
- Onukwulu, Ndidi
- Onuma, Parsley
- onumi
- Onur Bostancı (Alternative, Pop)
- Onural, Cengiz
- Onurr
- Onward (US band)
- Onward to Olympas
- Onward, etc.
- Onyanko Club
- Onyeabor, Charles
- Onyeabor, William
- Onyioha, Oby
- Onyria (Oniria)
- Onysus
- ONYVAA
- Onyx (New York hardcore rap group)
- Onyx (Israeli psytrance artist/DJ Yanniv Gold Farb)
- Onyx (IDM artist, track "Under Pressure")
- Onyx & Dope D.O.D.
- Onyx Collective
- Onyx feat. ASAP Ferg & Price, Sean
- Onyx feat. DMX
- Onyx feat. Dope D.O.D.
- Onyx feat. Genovese
- Onyx feat. Havoc
- Onyx feat. Makem Pay
- Onyx feat. Papoose & Cormega
- Onyx feat. Reks
- Onyx, PTX & Domestic
- Onze:20
- OOBE (Italian techno/house producer)
- OOBE (Polish Rock Band)
- Ooberfuse
- Ooberman
- Oobie (Tenaia Sanders)
- Oobik & the Pucks
- Oodaredevil (Yeat collaborator aka DareDevil)
- ooes
- oofoe
- Oohlas, The
- OOHYO
- ooi (German indie pop band)
- Ooi, Imee
- OOJA, Ms. (hiphop)
- Oojami
- Ookay
- Ookla the Mok (filk group)
- Ooklah the Moc
- Öökülm
- Oolacile
- oomiee
- Oomori, Kinuko (Japanese singer)
- Oomori, Seiko (Japanese pop/rock singer-songwriter)
- Oomph!
- Oomph! feat. Adel, den, Sharon
- Oomph! feat. Apocalyptica
- Oomph! feat. Hagen, Nina
- Oomph! feat. Harms, Chris
- Oomph! feat. Jandová, Marta
- Oomph! feat. L'ÂME IMMORTELLE
- Oomph! feat. L’Âme Immortelle
- Oompie Koerier
- Oona (Graphic artist born Oona Leganovic)
- Oona (Oona Garthwaite and Dave Tweedie)
