Authors beginning with O
- Johnny O'Brien
- Christian O'Connell
- David O'Connell
- Tyne O'Connell
- Jane O'Connor
- David O'Doherty
- Tom O'Donnell
- Chris O'Dowd
- Catherine O'Flynn
- Paul O'Grady
- Peader O'Guilin
- Mary O'Hara
- Mo O'Hara
- Sinead O'Hart
- Kate O'Hearn
- Dermot O'Leary
- Joan O'Neill
- Joe O'Neill
- Davy Ocean
- Ian Ogilvy
- Rex Ogle
- Ellen Oh
- Tola Okogwa
- Daniel Jose Older
- Jenny Oldfield
- Matt Oldfield
- Ben Oliver
- Jamie Oliver
- Jana Oliver
- Lauren Oliver
- Gregg Olsen
- Chibundu Onuzo
- Kenneth Oppel
- Nina Oram
- Wendy Orr
- Mary Pope Osborne
- Molly Know Ostertag
- Nick Ostler
- Alexandra Ott
- David Owen
- Karen Owen
- Loris Owen
- Panama Oxridge