- O
- OO
- OO
- OOak
- OakObi
- ObiObt
- ObuOce
- OceOct
- OctOdd
- Oddodo
- OdoOfa
- Ofaoft
- OGOh
- OhOhn
- OhnOK
- OKOkt
- OktOld
- OldOle
- OleOli
- OliOll
- OllOma
- OmaOme
- OmeOn
- OnOne
- OneOne
- OneOne
- OneOno
- OnoOom
- OomOpe
- OpeOpu
- OpuOra
- OraOrc
- OrcOre
- OreOri
- OriOrl
- OrlOrp
- OrpOrt
- OrtOsb
- OsbOsi
- Osi
- OstOti
- OtiOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOVT
- OvyOwn
- OwsOzb
- OZZ
- Orelsan feat. Neptunes, The
- Orelsan feat. Skread
- Orelsan feat. Stromae
- Orelsan feat. Thal, Ron “Bumblefoot”
- Oremuz
- Oren, Foreign
- Oren, Peter
- Orenstein, Janet
- Orenstein, Norman
- ORESAMA
- ORESKABAND
- Orestea (UK band)
- Oreya
- Orfeó Català
- Orff, Carl (composer)
- Orford, Martin
- Orgaanklap
- Organ (Finnish synth pop group)
- Organ Beats, The
- Organ Donor (Richmond, VA Death Metal Band)
- Organ Donor (early 2000s rock band)
- Organ Donors (hard dance group)
- Organ, Samuel
- Organ, The
- Organ, Tyne-James
- Organ, Willy (Belgian weirdo synthpop artist Simon Platteau)
- Organectomy (New Zealand brutal death metal)
- Organek, Tomek
- Organic Audio
- Organica
- Organismen (Swedish rapper)
- Organismen & Large, DJ
- Organismen & Large, DJ
- Organiz' (French R'n'B duo)
- Organización X
- Organización, La
- Organization, The (90s US funk metal band)
- Organized Family (Zambian music duo)
- Organized Konfusion (US alternative hip hop duo from Queens, NYC)
- Organized Konfusion feat. Hurricane G
- Organized Konfusion feat. Rude One, DJ
- Organized Noize (Atlanta hip-hop production group)
- Organized Rhyme
- Organizing Committee, The
- Orgel Sound J‐pop
- Orgi-E (Danish rapper)
- Orgone (US funk band)
- Orgone feat. de León, Adryon
- Orgone feat. Franklin, Fanny
- Orgonite (Rave band based in israel)
- Orgullo Nativo
- Orgy (US rock band)
- Orhan, Mahmut
- Orhan, Mahmut & Şener, Sena
- Orhan, Mahmut feat. Şener, Sena
- Orhan, Sevcan
- Orhon, Cüneyd
- Ori (folktronica singer songwriter Ori Alboher)
- Oriach, Riccie (Tropical artist from the dominican republic)
- Oriain, Charlie
- Oriakhi, Davina
- Orialus
- Oriana (Argentine model, actress and singer)
- Oriane Lacaille
- Orianthi
- Óriás
- Oribu
- Orielles, The
- Orient Expressions
- Orient Fall (modern progmetal band)
- Orient Pearl
- Oriental Sunshine
- Orientalis, Oceanvs
- Orientalis, Oceanvs & Mese, Idil
- Oriente (Rap group)
- Orig. Alpenland Quintett
- ORIGA (Russian singer active in Japan)
- Origami Angel
- Origami Tsunami (Alternative band from Manchester)
- Origami, Button
- Origamibiro
- Origene
- Origin (Kansas metal band)
- Origin Unknown (UK Drum & Bass producers Andy C & Ant Miles)
- Origin, The
- Originais do Samba, Os
- Original 3
- Original 7ven, The (formerly 'The Time')
- Original Alpenland Quintett
- Original Arzgebirgsche Randfichten