- O
- OO
- OO
- OO
- OOAF
- OAFOak
- OakObe
- OBEOBO
- OBOOcc
- OccOce
- OCEOct
- OctOCU
- OCUOdd
- OddODE
- ODEODU
- ODUOf
- OfOff
- OffOG
- OGOGX
- OhOh
- OhOHY
- OiOjo
- OjoOkd
- OKDOku
- OkuOla
- OlaOld
- OldOle
- OleOli
- OliOli
- OliOll
- OllOls
- OlsOma
- OmaOme
- OmeOmn
- OmnON
- OnOnd
- OndOne
- OneOne
- OneOne
- OneOnk
- ONLOno
- Onooof
- OogOpa
- OpaOpe
- OpOpp
- OppOra
- OraOra
- OraOrc
- OrcOrc
- OrcOre
- OreOrg
- OrgOri
- OriOri
- OriOrn
- OrnOrq
- OrqOrr
- OrsOrt
- OrtOsb
- OsbOsc
- OscOsl
- OslOst
- OstOte
- OteOtr
- OtrOtt
- OttOui
- OuiOus
- OutOut
- OutOut
- OutOuu
- OuvOve
- OveOvi
- OviOwe
- OweOwu
- OwuOya
- OyaOZI
- OZIozz
- Olari, Silvia
- OLAS
- Olas, Las
- Olasoji, Wale
- Olathia (Heavy metal band from Cleveland, Ohio)
- Olatuja, Alicia
- Olatuja, Michael (UK electric and acoustic bassist/composer, based in New York)
- Olatunji (alias for Olatunji Yearwood. Trinidadian soca artist.)
- Olatunji, Babatunde
- Olay, Ruth
- OLBRY
- Olcay, Zuhal
- Olcay, Zuhal & Onural, Cengiz
- Old (grindcore / industrial metal band, aka O.L.D.)
- Old (German black/thrash metal)
- Old & In the Gray
- Old & In the Way
- Old 97’s
- Old 97’s & Jennings, Waylon
- Old Abram Brown
- Old Accusers
- Old Again
- Old Apparatus
- Old Bear Mountain
- Old Best Friend
- Old Blind Dogs
- Old Blood (acid doom band from California)
- Old Breakout (blues rock)
- Old Caltone
- Old Canes
- Old Cat's Drama
- Old Cecil (UK prog folk/rock group)
- Old Ceremony, The
- Old City (Justin Mayer and MC/lyricist Tr38cho)
- Old Coke
- Old Corpse Road (UK / symphonic black metal with folk influences)
- Old Crow Medicine Show
- Old Crow Medicine Show feat. Ferrell, Sierra
- Old Crow Medicine Show feat. Staples, Mavis
- Old Crow Medicine Show feat. Watson, Willie
- Old Daisy
- Old Dead Tree, The
- Old Dogs
- Old Dominion (Hungarian black metal band)
- Old Dominion (US country band)
- Old Dominion (feat. Little Big Town)
- Old Dominion & Moroney, Megan
- Old Dominion feat. Knight, Gladys
- Old Dominion feat. Little Big Town
- Old Dominion with Moroney, Megan
- Old Fire
- Old Firm Casuals, The
- Old Flame (United States rock band feat. Jonny Craig)
- Old Funeral
- Old Glory & The Black Riviera
- Old Gods of Asgard
- Old Gods of Asgard feat. Wake, Alan & Mr. Door
- Old Gray
- Old Heavy Hands
- Old Horn Tooth
- Old Jim & Scarlett
- Old Jim, LUNAX & Kickbait
- Old Kerry McKee
- Old Loaves (New Zealand post rock/metal)
- Old Man Canyon
- Old Man Gloom
- Old Man Lizard
- Old Man Luedecke
- Old Man Luedecke & Bahamas
- Old Man Luedecke & Smith, Reeny
- Old Man Markley
- Old Man River
- Old Man Savage
- Old Man Saxon
- Old Man Winther
- Old Man Wizard
- Old Man's Will
- Old Man’s Child
- Old McBezen & Dungaree Dan
- Old Merry Tale Jazzband
- Old Mervs
- Old Moonshine Band
- Old Neon
- Old Night
- Old One
- Old Ox
- Old Paths, The
- Old Reliable String Band
- Old Romantic Killer Band, The
- Old Salt (Belgian Americana band)
