- O
- OO
- OO
- OOak
- OakObi
- ObiObs
- ObsOce
- OceOct
- OctOdd
- OddOdi
- OdiOf
- OfOFF
- OffOgr
- OgOha
- OhaOiz
- OJOka
- OKDOla
- OlaOld
- OldOle
- OleOli
- OliOls
- OlsOma
- OmaOmi
- OmiOn
- OnOne
- OneOne
- OneONE
- ONEOno
- OnoOom
- OomOpe
- OpeOpt
- OptORA
- OraOrc
- OrcOr
- OreOri
- Ori
- OriOro
- OroOrr
- OrsOs
- OsOsc
- OscOsm
- OsmOT
- OtaOts
- Ots
- Out
- OutOut
- OutOut
- OutOve
- OveOwe
- OweOx
- OXOzc
- OZZ
- One Day (Australian hip-hop)
- One Day Alive (Heavy Metal Band)
- One Day as a Lion
- One Day Hero
- One Day Remains (Based in Switzerland)
- One Dead Three Wounded
- One Desire (Melodic rock band from Finland)
- One Dimensional Creatures
- One Dimensional Man
- One Direction
- One Dollar Short
- One Dove
- ONE DRAFT
- One Drop (reggae group)
- One dying wish (Italian band)
- One eskimO
- One Eye Closed
- One Eyed Moon (garage/punk/stoner rock band from Atlanta, Georgia)
- One Fine Day (German rock/punk band)
- 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 Hundred Hours
- 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 Piece (electronic)
- One Piece Puzzle (Rock Band in the US)
- One Red Martian
- One Revolution
- One Ring Zero
- One Second 2 Late
- 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 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