- O
- Karen O
- Sinéad O'connor
- Tara Jane O'Neil
- Jim O'Rourke
- Oasis
- Agnes Obel
- Frédéric D. Oberland
- Conor Oberst
- Object
- Oboken
- Frank Ocean
- Ocean Colour Scene
- Oceansize
- Oddfellows Casino
- Odessey & Oracle And The Casiotone Orchestra
- Odezenne
- Of Montreal
- Of The Wand And The Moon
- Off Models
- Off!
- Oh No! Oh My!
- Ohgr
- The OhSees
- Oingo Boingo
- Oiseaux-Tempête
- Okada
- Okay
- Okkervil River
- Ol.
- The Old Dead Tree
- Old Time Relijun
- Will Oldham
- Charles C. Oldman
- Olen'k
- Nick Oliveri
- The Olivia Tremor Control
- Angel Olsen
- Om
- Omd - Orchestral Manoeuvres In The Dark
- Omega Massif
- OMR
- On
- On The Might Of Princes
- One Day As A Lion
- One Inch Punch
- One More Season
- One Time Angels
- One-Speed Bike
- Oneida
- Onelinedrawing
- Oneohtrix Point Never
- Yuji Oniki
- The Only Ones
- OOIOO
- Ooooo
- OP8
- Opac
- Open Mike Eagle
- Openheimer Analysis
- Operator
- Opeth
- The Opposition
- Orange Alabaster Mushroom
- Orange Goblin
- Orange Juice
- Oranger
- Oranssi Pazuzu
- Orb
- Orbital
- Orchestra Of Constant Distress
- Orchestre Tout Puissant Marcel Duchamp
- Orchid
- The Orchids
- Bill Orcutt
- Order
- The Organ
- Original Silence
- Orthrelm
- Beth Orton
- Orval Carlos Sibelius
- The Orwells
- The Oscillation
- Osculum Infame
- Oslo Telescopic
- The Others
- Christine Ott
- Ought
- Our Brother The Native
- Out Hud
- Outfit
- Outside The Air
- Overhead
- Overmars
- Ovuca
- Owlle
- Christine Owman
- Oxbow
- Oxes
- Oxmo Puccino
- Oysterhead
