- O
- OO
- OO
- OOak
- OakOb
- ObeObo
- OBOOce
- OceOch
- OchOct
- Odd
- OddODM
- ODOOf
- OfOff
- OFFOgr
- OgrOh
- OhOIR
- OirOKA
- OkaOku
- OkuOla
- OlaOld
- OldOli
- OliOli
- OliOls
- OlsOMA
- OmaOme
- OmeOmo
- OMPOnd
- One
- OneOne
- OneOni
- OniOno
- OnoOom
- OomOpe
- OpeOpp
- OppOra
- OraOrb
- OrbOrc
- OrcOrg
- OrgOri
- OriOrk
- OrkOrp
- OrpOrr
- OrrOrv
- OrvOsb
- OsbOsi
- OsiOst
- OstOth
- OthOtt
- OttOue
- OugOut
- OutOut
- OutOut
- OutOve
- OveOVR
- ovrOwl
- OwlOxx
- OxyOZR
- ozz
- Ostbahn, Kurt
- Ostbahn, Kurt & Kombo, die
- Ostbahn, Kurt & Ostbahn 11, Die
- Östblocket
- Ostblockschlampen
- Osted
- OsTEKKe
- Östen med Resten
- Oster Lapwass
- OSTER project
- Östermalm
- Ostermann, Willi
- Ostermann, Willi & Orchester
- österreich
- Ostertag, Florian
- Osterwald, Hazy (Swiss musician, singer and bandleader)
- Osterwald, Hazy, Sextett
- Ostinato (Jazzband)
- Ostkreutz
- OSTON
- ostooandell
- Ostoura, Hamo El
- Ostrar, Adam
- Ostrich Bouquet
- Ostrogoth (Belgian metal band)
- Ostrowska, Małgorzata
- Ostura (Lebanese Heavy/Power Metal)
- Ostyn (Project of Bert Ostyn)
- Ostzonensuppenwürfelmachenkrebs
- Osunlade
- Osunlade feat. Divine Essence
- Osunlade feat. Oveous Maximus
- Osvajači (Serbian hard rock/heavy metal band)
- Osvaldo (Los Angeles based beatmaker & producer)
- Osvaldo Ayala
- Osvaldorio (indonesian disc jockey and music producer)
- Oswald (Zouk Singer)
- Oswald, Marianne
- Oswaldir & Carlos Magrão
- Oswalt, Patton
- Oszajca, John
- Oszibarack
- OT (Belgian pop singer Olivia Trappeniers)
- OT7 Quanny
- Ōtaki, Yūko (singer)
- Otala (Post-rock quartet from Nottingham, UK)
- Otani, Kow (Japanese anime, film & video game composer)
- Ōtani, Tomoya
- Ōtani, Tomoya feat. Kirk-Holmes, Merry
- Ōtani, Tomoya feat. NateWantsToBattle
- Otargos
- Otarion
- otay:onii
- OtC
- OTE
- OTE feat. Ellis, Steven
- Otenki
- Otep
- Otero, Adrián
- Otero, David (00s Spanish musician)
- Otero, David & Adelén
- Otero, David & Basarte, Bely
- Otero, David & Carlos Sadness
- Otero, David & Cepeda
- Otero, David & Fernández, Dani
- Otero, David & Guerra, Ana
- Otero, David & Mäbu
- Otero, David & Soto, Marta
- Otero, David & Taburete
- Otero, David, Nil Moliner & Arnau Griso
- Otero, Manolo
- otetsu
- otetsu feat. GUMI
- Otey, Lisa
- OTF Boonie Moe
- OTF Boonie Moe, Rob49 & Only the Family
- Otgoo
- OTH
- Otha (Othalie Husøy)
- Othello (Théo Celino)
- other boys
- Other Colors, The
- Other Ego
- Other End, The (Norwegian duo)
- Other Favorites, The
- Other Guys, The (Scottish A Cappella Group)
- Other Guys, The (US hip-hop duo)
- Other Half, The (’60s San Francisco psychedelic rock band)
- Other Lives (US indie rock band)
- Other Men