- O
- OO
- OO
- OO
- OOak
- OakOat
- OatObi
- ObiObs
- ObsOce
- OceOce
- OceOct
- OctOdd
- ODDOde
- OdeODO
- odoOes
- OesOff
- OffOff
- OffOgr
- OGROh
- OhOHN
- OHNOjb
- OjeOKA
- OKAokt
- OktOLA
- OlaOld
- OldOle
- OleOli
- OliOli
- OliOlm
- OlmOlv
- OlvOma
- OmaOme
- OmeOmo
- OmoOna
- ONBOne
- OneOne
- Oneone
- oneONG
- OngOnl
- OnlOnu
- OnuoOo
- Ope
- OpeOpi
- OpiOpu
- OpvOra
- OraOrb
- OrbOrc
- OrcOrd
- OrdOrg
- OrgOri
- OriOri
- Oriorm
- OrnOrp
- OrqOrr
- OrrOrt
- OrtOsb
- OsbOsc
- OscOsm
- OsmOst
- OstOTH
- OthOtr
- OtsOtt
- OttOur
- OurOut
- OutOut
- OutOut
- OutOve
- Oveove
- OveOVX
- OvyOwl
- OwlOxl
- OxlOzc
- OzcOzu
- Ozuozz
- O’Callaghan, John feat. Howells, Sarah
- O’Callaghan, John Feat. Howells, Sarah
- O’Callaghan, John feat. Jaren
- O’Callaghan, John feat. Jaren
- O’Callaghan, John feat. Josie
- O’Callaghan, John feat. Josie
- O’Callaghan, John feat. Larkin, Betsie
- O’Callaghan, John feat. Lo-Fi Sugar
- O’Callaghan, John Feat. Lo-Fi Sugar
- O’Callaghan, John feat. Lo-Fi Sugar
- O’Callaghan, John feat. McKinney, Kevin
- O’Callaghan, John Feat. Ria
- O’Callaghan, John feat. Ria
- O’Callaghan, John featuring Ria
- O’Connell, Helen
- O’Connell, Helen & Dorsey, Jimmy and Orchestra, His
- O’Connell, Lauren
- O’Connell, Maura
- O’Connell, Robbie
- O’Connor (Argentine hard rock band)
- O’Connor, Blake
- O’Connor, Caroline
- O’Connor, Caroline & Bolton, John
- O’Connor, Cavan
- O’Connor, Des (English singer, lyricist)
- O’Connor, Donald
- O’Connor, Geoffrey
- O’Connor, Jennifer
- O’Connor, Mark (US bluegrass, country and classical fiddler/composer)
- O’Connor, Maz
- O’Connor, Paddy
- O’Connor, Sinéad (Irish singer‐songwriter)
- O’Connor, Sinéad feat. Blockheads, The
- O’Connor, Sinéad feat. U2
- O’Connor, Stuart (UK alternative)
- O’Day, Alan
- O’Day, Anita
- O’Day, Anita & Krupa, Gene
- O’Day, Anita & Three Sounds, The
- O’Day, Anita & Tjader, Cal
- O’Day, Anita with Kenton, Stan and His Orchestra
- O’Day, Anita with May, Billy
- O’Day, Aubrey
- O’Day, Molly (American country music vocalist)
- O’Death
- O’Dell, Brooks
- O’Dell, Kenny
- O’Dette, Paul (American conductor and lute player specialising in early music)
- O’Doherty, David
- O’Donis, Colby
- O’Donis, Colby feat. Akon
- O’Donis, Colby feat. Romeo
- O’Donis, Colby feat. T‐Pain
- O’Donis, Colby feat. Wall, Paul
- O’Donnell, Daniel
- O’Donnell, Daniel & Duff, Mary
- O’Donnell, Daniel with Billie Barry Kids, The
- O’Donnell, Daniel with Duff, Mary
- O’Donnell, Daniel with Rathdowney Choir & Presentation Secondary School Choir, The
- O’Donnell, Erin
- O’Donnell, Martin
- O’Donnell, Martin & Salvatori, Michael
- O’Donnell, Martin & Salvatori, Michael
- O’Donnell, Martin and Salvatori, Michael
- O’Donnell, Rosie
- O’Donnell, Ryan & Rachel
- O’Donoghue, Cian
- O’Donovan, Aoife
- O’Donovan, Aoife feat. Cunningham, Madison
- O’Donovan, Aoife feat. Mitchell, Anaïs
- O’Donovan, Aoife feat. Russell, Allison
- O’Dowda, David
- O’Duffy, Michael (Irish tenor)
- O’Dwyer, Áine
- O’Farrill, Chico
- O’Farrill, Chico & His Orchestra
- O’Farrill, Chico, y All‐Stars Cubano
- O’Flynn (London DJ and producer)
- O’Flynn, Liam
- O’G3NE (formerly “Lisa, Amy & Shelley”)
- O’Halloran, Dustin
- O’Halloran, Dustin & Bertelmann, Volker
- O’Halloran, Dustin & Gyða Valtýsdóttir
- O’Halloran, Dustin & Senti, Bryan
- O’Halloran, Dustin & Siggi String Quartet
- O’Halloran, Dustin, ACME String Quartet
- O’Hara, Catherine
- O’Hara, Jamie
- O’Hara, Jill
- O’Hara, Kelli
