- O Christmas Tree (Pan Pipes) Band
- O Come All Ye Faithful Band
- O Holy Night Band
- O Little Town Of Bethlehem Band
- O Tannenbaum
- O Tannenbaum Oh Tannenbaum
- O'Lee
- O'Neill & Jones
- O'Reilly Consort, The
- O.M.I. Academy
- O/RIOH
- Oasis Worship
- OBB
- Obe and Amber
- Obývačkový Orchester
- Octavian O.
- Octavians
- Odalager
- Odd Nordstoga
- Oddgeir Berg Trio
- Ode
- Odetta
- Odilio González
- Oeral Kozakkenkoor
- OffGrid Audio
- Oh Come All Ye Faithful Band
- Oh Jieun
- Oh! Paulo
- Okay
- Ola Gjeilo
- Ola W Jansson
- Olaf Berger
- Olaf Henning
- Olauka
- Olav Stedje
- Old 97's
- Old Man Gloom
- Old Spice
- Ole Edvard Antonsen
- Ole Evenrud
- Ole Steenen
- Oleg Marshev
- Olek Klepacz
- Oleta Adams
- Olga Bonczyk
- Olga Guillot
- Olga Konkova
- Olga Orange
- Oline Meland
- Oliver Jones
- Oliver Mason
- Oliver Mayo
- Oliver Schmitt
- Oliver Schott
- Oliver Scott
- Oliver Thomas
- Oliver Östbäck
- Olivia Baxter
- Olivia Best
- Olivia Creutzer
- Olivia Lane
- Olivia Mark
- Olivia Newton-John
- Olivia Stefani
- Olivier Caillard
- Olle Warm
- Olli Leppänen
- OloriAfrica
- Olov Österberg
- Omar Rodriguez Music
- Omar Sánchez Omi
- Ome Henk
- OMG en Alien
- Onbc
- Once In Royal David's City Band
- Oncle Gilbert
- One Man Army and the Undead Quartet
- One Man Band
- One More
- One Sound Designs
- One Voice
- One Voice Children's Choir
- OneRepublic
- Onika Charles
- Only Won
- Ony
- Opa Theo
- OpenGlobe
- Opera Da Club
- Operatica
- Operatika Element
- Opfekompott
- Opihi Pickers
- Opus 7 Vocal Ensemble
- Opus Jam
- Orange Kids Music
- Orbit
- Orchester Alfred Hause
- Orchester der Vereinigten Bühnen Wien
- Orchester Jo Kurzweg
- Orchester Joachim Kurzweg
- Orchestra Andrea e Lorena
- Orchestra Cabanas
- Orchestra e coro civico di Corato
- Orchestra of the Age of Enlightenment
- Orchestra of the Kirov Opera, St. Petersburg
- Orchestra Victoria
- Orchestre d'Auvergne
- Orchestre de Paris
- Orchestre Raymond Chevreux
- Orden y Mandato de San Miguel Arcangel
- Orestes Perrami
- Orf Symphony Orchestra
- Orfeón de Madrid
- Orfila
- Orig. Zirbitz Buam
- Orfila
- Orig. Zirbitz Buam
- Orig.Stille-Nacht-Solisten
- Original All-Stars
- Original Almrauschklang
- Original Broadway Cast Of Can Can
- Original Cast of Girl Crazy
- Original Harzer Rotkehlchen
- Original Naabtal Duo
- Original Zillertaler
- Orion
- Orions
- Orlando Consort
- ORP
- Orquesta de la plata
- Orquesta de Navidad
- Orquesta Havana
- Orquesta Raul Aguirre
- Orquesta Sinfónica Esperanza Azteca
- Orquesta Tipica Daniel Garcia Blanco
- Orquestra e Coro Fantasia
- Orrin Hatch
- Oscar Brand
- Oscar D'León
- Oscar Gibbons
- Oscar Johns
- Oscar Moore Trio
- Oscar Peterson
- Oscar Spear
- Oshri
- Oslo Fagottkor
- Oslo Gospel Choir
- Oslo Soul Children
- Ostatni w Raju
- Ostrobothnian Chamber Orchestra
- Osttiroler Freunde
- Oswald Sattler
- OTHERWISE
- Otis Read & Friends
- Otis Redding
- Oto Pestner
- Otoniel Rojas
- Otos
- Ottmar Liebert
- Otto Ackermann
- Otto Lechner
- Otto Pollard
- Out of Berlin
- Ove Engstrom
- Ove Verner Hansen
- Over the Rhine
- Overflow A Cappella
- Owain Park
- Owen Richards
- Owen Rochester Jazz
- Oxford Children's Choir
- Oxford St. Peter's Choir