- O
- OO
- OO
- OOak
- OakObi
- ObiObs
- ObsOCE
- OceOct
- octOdd
- OddOdi
- OdiOf
- OfOff
- OffOh
- ohohG
- OhgOji
- OJMokh
- OKIOla
- OlOld
- OldOli
- OliOli
- OliOls
- OlsOMB
- OMBOmn
- OmnOnb
- OncOne
- OneOne
- OneOni
- ONJont
- OntOos
- OotOph
- OphOR
- OrOrb
- OrbOrc
- OrcORE
- OreOri
- OriOrl
- OrlOrp
- OrpOrt
- OrtOsb
- OsbOsi
- OsiOst
- OstOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOvi
- OviOwl
- OwlOye
- Ozy
- OzzOZZ
- Orthodox (Spanish doom metal)
- Orthodox (Straight Edge)
- Orthodox Celts
- Orthostat
- orti (electronic/electroclash/techno project)
- Orties
- Ortiga (Chilean canto nuevo group)
- Ortiga (Former Esteban & Manuel member)
- Ortiz, Alfredo (player of the Paraguayan harp)
- Ortiz, Bill
- Ortiz, Coqui
- Ortiz, Gerardo (Regional Mexican singer)
- Ortiz, Joell (rapper fka Jo‐ell Quikman)
- Ortiz, Joell feat. Akon
- Ortiz, Joell feat. Bruja, La
- Ortiz, Joell feat. Immortal Technique
- Ortiz, Joell feat. Novel
- Ortiz, Kevin
- Ortiz, Luis “Perico”
- Ortiz, Paul y La Orquesta Son
- Ortolani, Riz
- Ortolani, Riz feat. Ranieri, Katyna
- Orton, Beth
- Orton, Beth feat. Callier, Terry
- Orton, Mark
- Ortopedia Técnica (Garage Punk band from Castellón de la Plana)
- ortoPilot
- Ortsul (Poland / Black Metal)
- Oruç, Mustafa
- Orup (Swedish musician Hans Thomas Eriksson)
- Orville Peck
- Orvokki
- Orwell (French band)
- Orwells, The
- Orxata Sound System
- Ory, Kid
- Oryad (doom metal/symphonic metal group)
- Oryema, Geoffrey
- oryl
- Orzabal, Roland
- OS (German duo)
- Os 3 do Nordeste
- Os Atuais
- Os Bardos
- Os Cretinos
- Os Dentes
- Os Extintos
- Os Garotin
- Os Mateadores
- Os Mulheres Negras
- Os Mundi
- Os Nativos (South-Brazilian gaucho music group)
- Os Pontos Negros
- Os Serranos
- Os The Darma Lóvers
- Os Tincoãs
- Os Vips
- Os Vips (Os Vips)
- OS101 (hardcore punk band)
- Osa (El Caco frontman Øyvind Osa's solo project)
- Osa, Liv Bernhoft (Norwegian actress)
- Osada Vida
- Osadebe, Stephen Osita, Chief
- Osaen
- Osage Tribe
- Osaka Flu
- Osaka Monaurail
- Osaka Popstar
- Osaka Punch (Australian rock band, formerly The Kidney Thieves)
- Osaka Syunkasyuto
- Osaki (jazz hop)
- Osaki ft. Sleepermane
- Osaki, Nana starring Nakashima, Mika
- Osama GBS
- OsamaSon (underground artist)
- Osanna
- Osanzi
- Osasioo (Canadian RnB Artist)
- Osatia
- Osawa, Shinichi
- Osay (American rapper, singer-songwriter)
- Osaze feat. Veda, Jaidene
- Osborn Abigail
- Osborne (Todd Osborn)
- Osborne Brothers, The
- Osborne Brothers, The & Allen, Harley "Red"
- Osborne Brothers, The & Wiseman, Mac
- Osborne, Anders (US singer-songwriter)
- Osborne, Bertín
- Osborne, Bobby