- O
- OO
- OO
- OOak
- OakObi
- ObiObs
- ObsOce
- OceOCT
- OctODD
- OddOdm
- ODMof
- OfOff
- OffOh
- OhOHK
- OhkOjo
- OjoOki
- OkkOla
- OLAOld
- OldOli
- OliOli
- OliOls
- OlsOme
- OmeOmn
- OmnOnc
- One
- OneOne
- OneOnl
- OnlONY
- OnyOpe
- OpeOpi
- OpiOra
- OraOrb
- OrbOrd
- OrdOrg
- OrgOri
- OriOrm
- OrmOrq
- OrqOrw
- OrxOsc
- OscOsl
- OsmOsz
- OszOts
- Ots
- Out
- OutOut
- OutOut
- OutOve
- OveOwe
- OweOxf
- Oxf
- OZZ
- Oakey, Philip & Moroder, Giorgio
- Oakey, Philip & Moroder, Giorgio
- Oakey, Philip with Moroder, Giorgio
- Oakhands
- OAKK
- Oakk, Breezy
- Oakland, Guy
- Oakland, Max
- Oakley Riot
- Oakley, Michael (U.K. synthwave artist/producer)
- Oakley, Michael feat. Phoenix, Dana Jean
- Oakman (French band)
- Oaks & Fahia (Spanish prog group)
- Oaks, Chris (christian rapper)
- OaKs, The
- Oaktree (Belgian electronic music producer)
- Oakwite
- Oakwood Station
- Oar (Australia, Metal)
- Oasis (1991–2009 Britpop)
- Oasis (Omar-S and Shadow Ray)
- Oasis (’70s US rock band)
- Oasis 4you (Mexican Christian music group)
- Oasis Chorale
- Oasis Worship
- Oates, Jackie
- Oates, John
- Oath (An alias of Steven Waddell, used in this Heavy Metal solo project based in Edinburgh, Scotland, UK, started in 2018.)
- Oath to Order (USA metalcore/deathcore)
- Oath, Das
- Oath, The (German heavy doom metal)
- Oathbreaker (Belgian post-black metal band)
- Oathless
- Oaths, The
- Oatmello
- Oattes, Bernard
- Oaty. (lo‐fi artist)
- OAU (OVERGROUND ACOUSTIC UNDERGROUND)
- OB (DnB Producer (North London))
- OB OBrien feat. Drake & Preme
- Oba Oba Samba House
- Obadiah Parker
- Obake
- Öbarna
- Obas, Beethova
- Obata, Takahiro (jazz pianist, keyboardist)
- OBB (Oswald Brothers Band)
- Obbie Messakh (Artist of JK Records)
- Obe Dve
- Obè, Amir
- Obè, Amir feat. PARTYNEXTDOOR
- Obè, Amir feat. Sostre, Eli
- Obed Marsh (Australian black/doom metal)
- Obel, Agnes (Danish singer)
- Oben, Cahit
- Obenski, Amy
- Oberbaum (German/Belgian artist Lucie Rezsöhazy)
- Oberer Totpunkt
- Oberg
- Öberg, Mats
- Oberhofer
- Oberhofer, Brad
- Oberlin, Karen
- Oberpichler, Rale
- Oberritter Dóra ft. Lotfi, Begi
- Oberschlesien
- Oberst, Conor
- Oberst, Conor and Mystic Valley Band, The
- Obese Turtles, The (Kimya Dawson side project)
- Obeses
- Obey the Brave
- Obey, Ebenezer
- OBGMs, The
- Obi (UK britpop band)
- Obi Best (formerly called Colorforms)
- Obia le Chef
- Obia le Chef avec Caballero & JeanJass
- Obia le Chef feat. Tizzo
- Obiat
- Obibox
- Obie Hans
- Obiedo, Ray
- Obieglo, Andreas
- Obispo, Pascal
- Obispo, Pascal & Alexia Gredy
- Obispo, Pascal & Angi, Giordana
- Obispo, Pascal & Frégé, Élodie
- Obispo, Pascal & Mars, Mélissa
- Obispo, Pascal & St-Pier, Natasha
- Obispo, Pascal avec Zazie