- Our Broken Garden
- Once We Were
- OJ Da Juiceman
- Outmatch
- Old Time Relijun
- Orlando "Cachaito" Lopez
- Oh No! Oh My!
- Outrageous Cherry
- Oh Atoms
- Où est le Swimming Pool
- Oboken
- Obits
- Ohm Guru
- Oleander
- Orleans
- October Fall
- Onur Özer
- On Travel
- One Second Bridge
- Only Seven Left
- Oren Bloedow
- Orange Blossom
- Outloud
- Oppressed by the Line
- One Last Look
- Ov Hell
- Oliver Lake
- Oli Brown
- Odd Nosdam
- Olivia the Band
- Oppressor
- Other Mountains
- Oscar Moore
- Opio
- Oszibarack
- Otyg
- Othar Turner
- Ohbijou
- Old Man Luedecke
- Omela
- Oscar Pettiford
- Once Blue
- Orealis
- Ot Azoj Klezmerband
- Ondskapt
- Os Paralamas do Sucesso
- Oubliette
- On Fire
- Oscar Castro-Neves
- Orange 9mm
- Officium Triste
- Opus Nigrum
- One Without
- Oxbow
- Overflow
- One Way Mirror
- Oliver Jones
- Origa
- Orkrist
- Obehag
- Owana Salazar
- Over It
- Ordo Templi Orientis
- One Day as a Lion
- Odean Pope
- Octopus
- Old Wainds
- Orange Factory
- Open Space
- Otoe
- Our People Versus Yours
- Open Mind
- Overthrow
- Orchid
- Overland
- Orchestre National de Barbes
- Ophthalamia
- OP8
- Ohm:
- Ordog
- Oteil Burbridge
- Ollabelle
- Only Son
- Outersect
- Oskar Hallbert
- One Little Plane
- Oceana
- Orion Rigel Dommisse
- Ostinato
- Orcivus
