- 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
- Omnia & Gallagher, Audrey
- Omnia & Ira
- Omnia feat. Burns, Christian
- Omnia feat. Loretta, Melissa
- Omnia feat. Nadeau, Danyka
- Omnia feat. Rose, Jonny
- Omnia feat. Wrigsell, Tilde
- omniboi
- omniboi feat. Fantasyluv
- omniboi feat. Zeph
- Omnific, The
- Omnific, The ft. Gober, Clay
- Omnihility
- Omnikrom
- Omnikrom ft. TTC
- Omnimar
- Omnimotion
- Omnioid
- Omnis (ambient / drone)
- Omnisoul
- Omnispawn
- Omnitica
- Omnitron (Thrash Metal band from Sweden)
- Omnium Gatherum
- Omnivide
- Omnivortex
- OMNOM (Tech House artist)
- Omnyama, Mfaz'
- Omodaka
- Omodaka (Soichi Terada)
- OMOH (Pop electro french duo)
- Omoinotake
- Omonoko (Northern Irish Alt pop quartet)
- OMORI (Composers of the video game soundtrack “Omori”)
- Omori, Cullen
- Omori, Hinako
- Ōmori, Toshiyuki
- Omosumo
- Omotola
- OMP
- Omp El Capitán (Dominican Christian music singer)
- OMR (French Rapper)
- Omri (emo electro)
- Oms, Kuba (Canadian soul singer and producer)
- Omul cu Șobolani
- Omulu + King Dou Dou
- OMY, The
- ON (Sylvain Chauveau and Steven Hess with rotating guest artists)
- ON (solo project of Ken Andrews)
- ON (Hardcore)
- on a créé un monstre
- On a Dead Machine
- On a Friday (pre‐Radiohead group, until 1991)
- On a Hiding to Nothing
- ON AN ON
- On Atlas’ Shoulders
- On Being an Angel
- On Being Human
- On Broken Wings
- On Call Heroes
- On Camera
- On Dead Waves
- On Inc.
- On My Honor
- On Planets & Flaws
- On Solid Ground
- On the Last Day
- On the Line All-Stars, The
- On the Loose (doom metal band from Portugal)
- On the Might of Princes
- On the Rocks (all male a cappella group from the University of Oregon)
- On Thorns I Lay (death/doom/gothic metal band from Greece)
- On Thorns I Lay (French Doom Metal Band)
- On Tonight
- On Video
- On Wave (indie)
- On-lyne (Warframe fictional boy band)
- ON-OFF (AC/DC cover band from northern Italy)
- On-The-Go
- ON/OFF (Japanese Band)
- Ona Nua
- ONAIR
- Önal, Ayşe Hatun
- Önal, Füsun
- Onar (Polish MC)
- Onarsé
- Onasis, Ariez
- Onasis, Ariez feat. Cossom, Kevin
- Onasis, Erick
- Oñate, Jorge
