- O
- OO
- OO
- OOak
- OakObe
- Obs
- ObsOce
- OceOck
- OckOcu
- OcuOd
- ODEOdo
- OdoOfe
- OfeOff
- OffO
- OGXOHE
- OhGOJ
- OJOka
- OkaOl
- OlOld
- OldOle
- OleOli
- OliOli
- OliOlu
- OluOmb
- OmbOmn
- OmnO
- OnaOne
- OneOne
- OneONE
- OneOnl
- Onlooi
- OoiOpe
- OpeOpp
- OppOra
- OraOrb
- OrbOrd
- OrdOrg
- OrgOri
- OriOrl
- OrlOrp
- OrpOrt
- OrtOs
- OsOsc
- OscOsm
- Osm
- Otr
- OtrOtt
- OTTOur
- OurOut
- OutOut
- OutOve
- OveOvi
- OviOwi
- OwlOxt
- Oxx
- OZZ
- One Flew South
- One Flew West
- One for All (Jazz Group)
- One for the Team
- One for the Team (Indie Rock band from Minneapolis MN)
- One Hello World
- One Hidden Frame
- One Hit Wonder (California punk band)
- One Hope
- One Horse Band
- One Hundred Hours
- One Hundred Hurricanes
- One Hundred Steps (Portugese post-hardcore band)
- One Hundred Year Ocean
- One Hundred, The
- One I Cinema
- One in a Million (1960s Scottish psychedelic band)
- One in a Million (Dutch rock/ska band)
- One In The Chamber (Rock Band)
- One Inch Giant
- One Inch Punch (grunge/hip hop duo from Los Angeles)
- One King Down
- One Last Glance
- One Last Wish
- One Less Reason
- One Life Crew
- One Light Out
- One Machine
- One Man
- One Man and His Droid
- One Man Army (USA punk band)
- One Man Army and the Undead Quartet
- One Man Boycott (One Man Boycott (Band))
- One Minute Silence
- One More Girl
- One More Time
- One Morning Left
- One Nation Crew (gospel vocal)
- One Nation Under (American metalcore band)
- One Night Only
- One Night Rodeo
- One Night Stand (Punk rock from Belgium)
- One of a Kind (rock band)
- One of the Last
- One of Us
- ONE OK ROCK
- ONE OK ROCK feat. 5 Seconds of Summer
- ONE OK ROCK feat. Carter, Tyler
- ONE OK ROCK feat. Gaskarth, Alex
- ONE OK ROCK feat. Lavigne, Avril
- ONE OK ROCK feat. Swims, Teddy
- ONE OK ROCK featuring Quinn, Kellin from Sleeping with Sirens
- ONE PACT
- One Path
- One Piano
- One Piece (electronic)
- One Piece Puzzle (Rock Band in the US)
- One Red Martian
- One Revolution
- One Ring Zero
- One Second 2 Late
- One Second Thought (New York City hardcore band)
- One Self
- One Sentence. Supervisor
- One Shot (French hip-hop collective)
- One Six Conspiracy
- One Sixth of Tommy
- One Small Step For Landmines
- One Sonic Society
- One South Lark
- One Step Beyond (experimental death metal band from Adelaide, Australia)
- One Step Beyond (Hardcore band from Berlin, Germany.)
- One Step Beyond (hip-hop trio Joe Summa, Val Black & Dee Cutz)
- One Step Beyond (electronic/house artist Wilson Santos)
- One Step Beyond (Belgian group)
- One Step Closer (hardcore)
- One Step Out
- One the Juggler
- One Time Weekend
- One Ton
- One Track Mind (track "I Like U")
- One True God
- One True Pairing (project of Tom Fleming, formerly of Wild Beasts)
- One True Thing
- One True Voice
- One Two (Danish pop group)
- One Two Trio
- One Up Downstairs, The
- One Voice (Filipino-American R&B girl group)
- One Voice
