- O
- OO
- OO
- OOak
- OakObi
- ObiObt
- ObuOce
- OceOct
- OctOdd
- OddODO
- ODOOf
- OfOfo
- OfrOH
- ohOhn
- OhnOK
- OkOkr
- OksOld
- OldOld
- OldOli
- OliOll
- OllOMA
- OmaOme
- Omeon
- OnOne
- OneOne
- OneOne
- OneOnl
- OnlOom
- OomOpe
- OpeOpt
- Ora
- Oraorc
- ORCOre
- OreOri
- OriOrk
- OrkOrp
- OrpOrt
- OrtOsb
- OsbOSI
- OsiOst
- OstOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOvn
- OvnOwl
- OwlOz
- OzOZZ
- Onlyfriend
- OnlyOneOf (South Korean boy group)
- Onmens (Belgian duo)
- Onmyo-za
- Ono, Daisuke
- Ono, Erena
- Ono, Lisa
- Ono, Masatoshi
- Ono, Yoko (Japanese-American musician and artist)
- Ono, Yoko feat. Audé, Dave
- Ono, Yoko feat. Death Cab for Cutie
- Ono, Yoko feat. Lennon, Sean
- Ono, Yoko feat. Miike Snow
- Ono, Yoko feat. Penguin Prison
- Ono, Yoko feat. Peter Bjorn and John
- Ono, Yoko feat. Portugal. The Man
- 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)
- Onrust (Dutch 2000s black metal)
- Onrust (Belgian post-metal band)
- 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
- 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. 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
- 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!