O-3
- One Morning In Spring
- One Morning Left
- One Nation Crew
- One Night Only
- One Off The Pace
- One Ok Rock
- One Pound Fish Man
- One Republic
- One Republic feat. Timbaland
- One Ring Zero
- One Session
- One Shot
- One Sock Thief
- One Star Story
- One Step Too Many
- One Strike Left
- One T feat. Cool T
- One Take
- One thing remains
- One Trip
- One True Pairing
- One True Voice
- one twelve
- One Voice
- One Way
- One Way System
- One Way To Kansas
- One Week Notice
- One Without
- One World
- One Worship
- One Year Later
- One(8)Seven
- One-Eyed Doll
- One-T
- One-T and Cool-T
- One.Be.Lo
- One:Day:Life
- OneChot
- ONEFOUR
- Onegai Twins
- Oneida
- Onelight
- Oneohtrix Point Never
- ONER
- OneRepublic
- OneStarCity
- Onething Live
- ONEUS
- Onew (SHINee)
- ONEWE
- Onewerd
- OneWorld
- ONF
- Ongoing Concept (The)
- ONHEL
- ONI
- Onicks
- Onion Brothers (The)
- Onirica
- Onita Boone
- Onitsha
- Onk Lou
- Onkel Hotte
- Onkel Tom
- Onkel Zwieback
- Onlap
- Online
- Online Euphoria
- Only
- only attitude counts
- Only Boys Aloud
- Only Case
- Only Children (The)
- Only Crime
- Only Girl
- Only Girls
- Only Innocent Die
- Only Ones (The)
- Only Seven Left
- Only The Family
- Only The Young
- OnlyReal
- Onnix
- ONR
- Ontologia
- ONUKA
- Onur
- Onur Akin
- Onur Mete
- Onur San
- onwhenready
- Ony Martos
- Onya Gray
- Onyx
- Onyx Colony
- Onyx Creación Divina
- Onze
- Onze:20
- OOFT!
- Oohlas (The)
- Ookay
- Oomhp
- Oomp Camp
- Oomph
- Oomph!
- Oonagh
- ooops
- OOVEE & Flatdisk
- Oowee
- OP 2
- Op jot Kölsch
- Op zoek naar Nemo
- Opa
- Opa Tsupa
- Opa Unger
- Opanso je ljubiti
- Opérettes
- OPB
- Open (The)
- Open Air Stereo
- Open Hand
- Open Mike Eagle
- Open Minded
- Open the Nile
- Open The Skies
- Open Water
- Openfire
- Openside
- Opera - Ludwig Is Alive
- Opera De Nuit
- Operación Triunfo 2017
- Operación Triunfo 2018
- Operación Triunfo 2020
- operacion triunfo 1
- Operation
- Operation Ivy
- Operation M.D. (The)
- Operation Semtex
- Operator Please
- Opeth
- OPFuture
- Ophélie Cassy
- Ophélie Winter
- Ophelia
- Ophelias (The)
- Ophelya
- Ophidian
- Ophiocordyceps
- Opi The Hit Machine
- Opia
- Opiúm
- Opiium
- Opio
- Opium Baby
- Opiuo
- OPM
- Opodeldox
- Opossom
- Oppnox
- OppositE
- Opposite Sounds
- Optical 2
- Optik Army
- Optikhelden
- Optimale Härte
- Optimo
- Optimus
- Opus Aeterna
- Opus Dai
- Oques Grasses
- OR
- Ora Maté
- Oracle
- Oral Bee
- Oran 'Juice' Jones
- Orange And Lemon
- Orange Black
- Orange Grove
- Orange Skyline
- Oranus Lassus
- Oré
- Orba Squara
- Orchestraccia
- Orchestral - The Party Has Just Begun
- Orchestral Manoeuvres In The Dark
- Orchestral Manoeuvres In The Dark (OMD)
- Orchestre Alan Record
- Orchestre Lamoureux
- Orchid
- Orchid Ablaze
- Ordarada
- Ordeal (The)
- Ordeal By Fire
- Orden Ogan
- Order Of Chaos
- Order Of Ennead
- Order Of Era
- Order Of Israfel (The)
- Order Of The Ebon Hand
- Order Of The Fly (The)
- Ordinary Boys (The)
- Ordinary Chill
- Ordinary World
- OrelSan
- Oren Lavie
- Oren Waters
- Orenda Fink
- Oreslan
- Organ (The)
- Organiz
- Organized Konfusion
- Organized Noize
- Orgasmic & Fuzati
- Orgasmus & Schwartz
- Orgânico
- Orgi69 & Bass Sultan Hengzt
- Orgie 69
- Orginal Naabtal Duo
- Orgone
- Orgy
- orhan
- orhan ölmez
- Orhan Gencebay
- Orhan Gencebay & Sibel Can
- Orhan Hakalmaz
- Orhan Rexhepi
- Ori Shochat
- Oriana
- Oriana Leotta
- Orianthi
- Orielles (The)
- Oriente
- Orietta Berti
- Origami - Larila Song
- Origami Horses
- Origene
- Original 4 Tiroler Buam
- Original 7ven
- Original Alpenland Quintett
- Original Animals (The)
- Original Banda El Limón
- Original Broadway Cast of Dear Evan Hansen
- Original Cast Vienna
- Original Flavor
- Original H
- Original Kiss
- Original Maintaler
- Original Nielsen Brothers
- Original Sicilian Style
