- O
- OO
- OO
- OOak
- OakObi
- ObiObs
- ObsOce
- OceOct
- OctOdd
- OddOde
- OdeOef
- OehOff
- OffOgd
- OgdOh
- OhOi
- OiOk
- okOku
- OkuOld
- OldOld
- OldOli
- OliOli
- OliOls
- OlsOMB
- OMBOmn
- OmnO
- OnaOne
- OneOne
- OneOng
- OngOno
- OnoOom
- OomOpe
- OpeOpt
- optOra
- OraOrc
- OrcOrd
- OrdOrh
- OrhOri
- OriOrm
- OrmOrq
- OrqOrt
- OrtOsb
- OsbOsi
- OsiOst
- OstOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOve
- OveOwe
- OweOxl
- OxlOzm
- OZMOZZ
- Orquesta Revé
- Orquesta Serenata Tropical
- Orquesta Sinfónica Nacional (Argentina - previously known as "Orquesta Nacional del Estado" (1948-1955))
- Orquesta Sinfónica Nacional de Costa Rica
- Orquesta Sublime
- Orquesta Tabaco y Ron
- Orquesta Típica Fernández Fierro
- Orquesta Típica Misteriosa Buenos Aires
- Orquesta Típica Tanturi
- Orquesta Todos Estrellas (Cuban orchestra (All Stars) with various artists from Egrem label)
- Orquesta Zodiac
- Orquestra Afro-Brasileira
- Orquestra Alada Trovão da Mata
- Orquestra Brasileira de Música Jamaicana
- Orquestra Contemporânea de Olinda
- Orquestra Imperial
- Orquestra Voadora (Brazilian brass band)
- Orquestra Was
- Orr, Benjamin (co-lead singer for The Cars)
- Orr, David
- Orr, Marty Christopher (Musical artist from Arkansas)
- Orr, Scott
- Orrall, Robert Ellis (US country singer/producer)
- Orrantia, Hayley (US actress and singer)
- Orrason, Máni
- Orrico, Stacie
- Orrje, Carl, Piano Ensemble
- Orry Jackson (German singer and songwriter)
- Orsa spelmän
- Orselli, Folco
- Orsen
- Orsen, Jack
- Orsen, Jack & Taktloss
- Orsenna, Erik
- Orsi
- orso, L' (Italian band)
- Orsolics, Hans
- Orson (00s US power pop band)
- Orsons, Die
- Orsons, Die feat. Cro
- Orsons, Die feat. Maxim
- Orsons, Die feat. Mine
- Orta, Choco
- Orta, Manuel
- Orta, María (Puerto Rican Christian music singer)
- Ortaç, Serdar
- Ortaçgil, Bülent
- Ortaçgil, Bülent & Kızılok, Fikret
- Ortaçgil, Bülent & Teoman
- Ortak, Svaba (rapper from Austria)
- Ortega, Anthony (jazz saxophonist)
- Ortega, Anthony, Trio
- Ortega, Emanuel
- Ortega, Fernando
- Ortega, Jeannie
- Ortega, Jeannie feat. Papoose
- Ortega, José (designer)
- Ortega, Lindi
- Ortega, Michael
- Ortega, Paco
- Ortega, Palito
- Ortegon, Sr (José Miguel Ortegón)
- Ortelli, Paolo
- Ortelli, Paolo, Matrix, DJ, Party Boomers feat. C, Jay
- Ortero, David
- Orth, Marisa
- Orthentix
- Orthodox (Spanish doom metal)
- Orthodox (Straight Edge)
- Orthodox Celts
- Orthostat
- orti (electronic/electroclash/techno project)
- Orties
- 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
- Ortize, Brian
- Ortolani, Riz
- Ortolani, Riz feat. Ranieri, Katyna
- Orton, Beth
