- O'Reillys And The Paddyhats, The
- O.A.R.
- O.C.
- O.Torvald
- O.W.S.
- Oak
- Oasis
- Obey the Brave
- Obie Trice
- Obituary
- Oceana
- Ocean Collective, The
- Ocean Jet
- Oceanlab
- Oceano
- Oceans Divide
- October Fall
- October Tide
- Odd Future
- ODESZA
- Oehl
- Ofelia K
- Ofenbach
- Ofenbach & Ella Henderson
- Off Bloom
- Offer Nissim
- Offset
- Offspring
- Offspring, the
- Of Mice & Men
- Of monsters and men
- Of Montreal
- Ofra Haza
- Of the Wand & the Moon
- of Verona
- Of Virtue
- Oh, Hush!
- Oh, Sleeper
- Oh Hellos, the
- Oh Honey
- Oh The Larceny
- Oh Wonder
- Oingo Boingo
- Oi Polloi
- Oi Va Voi
- Okean Elzy (Океан Ельзи)
- OK Go
- Okkervil River
- Ol' Dirty Bastard
- Ol' Dirty Bastard
- Ola
- Olafur Arnalds
- Olafur Arnalds and Arnor Dan
- Old Crow Medicine Show
- Old Daisy
- Old Man Canyon
- Oleander
- Oleg Chubykin
- Olexesh
- Olga Tanon
- Oliver Dragojević
- Oliver Heldens
- Oliver Heldens & Anabel Englund
- Oliver Koletzki
- Oliver Moldan
- Oliver Tree
- Oliver Tree & Little Big
- Oliver Tree & Robin Schulz
- Olivia Addams
- Olivia Holt
- Olivia Jane
- Olivia Millerschin
- Olivia Newton-John
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia O'Brien
- Olivia Ong
- Olivia Rodrigo
- Olivver The Kid
- Olly Murs
- Olsson
- Omar & The Howlers
- Omara Portuondo
- Omarion
- OmenXIII
- Omi
- Omkara
- Omnia
- Omnikid
- OMNIMAR
- Omnium Gatherum
- On-The-Go
- One-Eyed Doll
- One Bit
- One Direction
- One eskimO
- One Less Reason
- One Love
- One Night Only
- Oneohtrix Point Never
- One OK Rock
- OneRepublic
- Onestep
- One Week Wonder
- Onion
- on level
- Only The Young
- ONUKA
- Onyay Pheori
- Onyx
- Oomph!
- Oonagh
- Open Chapter
- Openside
- Opera Magna
- Opeth
- Opia
- Opus
- Oranger
- Orchestral manoeuvres in the dark (OMD)
- Orden Ogan
- Ordo Rosarius Equilibrio
- Oren Lavie
- Orgy
- Orianthi
- Orion Experience, the
- Orishas
- Orleans
- Ortal
- Orthodox
- Oscar And The Wolf
- Oscar Benton
- Oscarcito
- Oscar Zia
- Osmonds, the
- Os Mutantes
- Ost+Front
- Otep
- Other Lives
- Otherwise
- Otilia
- Otis Redding
- Oto Nemsadze
- Ottawan
- Otto Knows
- Oublaire
- Our Lady Peace
- Our Last Night
- Ourlives
- Our Mirage
- Outburst, The
- Outfield, the
- OutKast
- Outlandish
- Outline in color
- Out With The Old
- Overkill
- Over the Rhine
- Ovy On The Drums, Piso 21 & Blessd
- Owl City
- Ozuna
- Ozzie
- Ozzy Osbourne