- O
- OO
- OO
- OOak
- OakObi
- ObiObt
- ObtOce
- OceOct
- OctOdd
- OddODM
- ODOOf
- OfOfn
- OfnOh
- OhOhm
- OhmOK
- OKOkm
- OKOOla
- OlaOld
- OldOli
- OliOll
- OllOly
- OlyOME
- OmeOMP
- OmpOnD
- OneONE
- ONEOne
- OneOnl
- OnlOOJ
- OojOpe
- OpeOpp
- OppOra
- OraOrc
- OrcOre
- OreOri
- OriOri
- OriOrp
- OrpOrs
- OrtOsa
- OsaOse
- OshOss
- OssOth
- OthOtt
- OttOur
- OurOut
- OutOut
- OutOve
- OveOvi
- OviOwl
- OwlOxy
- OyOzu
- OzuOZZ
- Ossicles
- Ossie All Stars
- Ossifar (latin rock group)
- Ossler
- Ossomancer (USA / Black Metal)
- Ost & Kjex
- Ost & Meyer with Speed, Ronski & Kanell, Cate
- Ost & Meyer with Speed, Ronski and Kanell, Cate
- Ost, Timmy (Christian music singer)
- Ost+Front
- Ost+Front mit Aicrag, Erk
- Ost+Front mit B. Deutung
- Osta Love
- Ostava
- Ostbahn-Kurti & die Chefpartie
- Ostbahn-Kurti & die Chefpartie mit Brühl, Elisabeth von
- Ostbahn, Kurt
- Ostbahn, Kurt & Kombo, die
- Ostbahn, Kurt & Ostbahn 11, Die
- Östblocket
- Ostblockschlampen
- Osted
- OsTEKKe
- Östen med Resten
- Oster Lapwass
- OSTER project
- Ostermann, Willi
- österreich
- Ostertag, Florian
- Osterwald, Hazy (Swiss musician, singer and bandleader)
- Osterwald, Hazy, Sextett
- Ostinato (Jazzband)
- OSTON
- ostooandell
- Ostoura, Hamo El
- Ostrar, Adam
- 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
- Osvaldo (Los Angeles based beatmaker & producer)
- Osvaldo Ayala
- Osvaldorio (indonesian disc jockey and music producer)
- Oswald, Marianne
- Oswaldir & Carlos Magrão
- Oswalt, Patton
- Oszajca, John
- Oszibarack
- OT (Belgian pop singer Olivia Trappeniers)
- Otai, Mounir
- Otani, Kow
- 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, Manolo
- Otey, Lisa
- OTF Boonie Moe, Rob49 & Only the Family
- Otgoo
- Otha (Othalie Husøy)
- other boys
- Other Colors, The
- Other Ego
- 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
- Other Men
- Other Minds (Alternative Rock Band)