Paul Oakenfold
Philip Oakey
Berry Oakley
John Oates
David Oberlé
Ciarán Ó Braonáin
Joel O'Brien
Tim O'Brien
Fiachna O'Broainain
Alan O'Bryant
Ric Ocasek
Billy Ocean
Lucky Oceans
Colm O'Ciosoig
Eliades Ochoa
Phil Ochs
Chris O'Connell
Maura O'Connell
Charles O'Connor
Mark O'Connor
Sinéad O'Connor
Bill Oddie
Henry Oden
Odetta
Micheál Ó Domhnaill
Joe O'Donnell
Roger O'Donnell
Rosie O'Donnell
Noel Ó Dúgáin
Pádraig Ó Dúgáin
Esther Ofarim
Jamie O'Hara
Mary Margaret O'Hara
Brendan O'Hare
Patrick O'Hearn
Damien O'Kane
Leo O'Kelly
Bragi Olafsson
Babutunde Olatunji
Jamie Oldaker
Mike Oldfield
Molly Oldfield
Sally Oldfield
Terry Oldfield
Spooner Oldham
Will Oldham
Christy O'Leary
Darek Oles
Davy O'List
Graham Oliver
Janis Oliver
Kristine Oliver
Kristina Olsen
Nigel Olsson
Stephen O'Malley
Liam Ó Maonlaí
Michael Omartian
Damian O'Neill
Eoghan O'Neill
John O'Neill
Keith O'Neill
Mike O'Neill
Yoko Ono
Roy Orbison
William Orbit
Cait O'Riordan
Even Ormestad
Margret "Magga" Örnolfsdóttir
Jim O'Rourke
Benjamin Orr
Bobby Orr
Tony Ortega
Beth Orton
Roland Orzabal
Anders Osborne
Joan Osborne
Joe Osborne
Sonny Osborne
Ozzy Osbourne
Paul Oscher
Cherisse Osei
Paul O'Shaughnessy
KT Oslin
Donny Osmond
Michael O'Suilleabhain
Jacquie O'Sullivan
Clyde Otis
Johnny Otis
Shuggie Otis
Peter O'Toole
Steve Overland
Buck Owens
Calvin Owens
Charles Owens
Paul Owens
Tim "Ripper" Owens
Bryan Owings
Adrian Oxaal
Tony Oxley
Monty Oxy-moron
Frank Oz