Featured Authors
Authors

= Author On Tour
- Alexandra O'Brien
- Anne O'Brien
- Anne Sibley O'Brien
- Bob O'Brien
- Chris O'Brien
- Dan O'Brien
- Eileen O'brien
- John O'Brien
- Juliette O'Brien
- Keith O'Brien
- Lucy O'Brien
- Maureen O'Brien
- Meg O'Brien
- Michael O'Brien
- Siobhan O'Brien
- Steve O'Brien
- Tim O'Brien
- Karyn O'Bryant
- Chelsea O'Byrne
- Ellen O'Clover
- Bishop O'Connell
- Caitlin O'Connell
- Catherine O'Connell
- David O'Connell
- Mark O'Connell
- Robert L. O'Connell
- Timothy E. O'Connell
- Patricia T. O'Conner
- Anahad O'Connor
- D'Arcy O'Connor
- Flannery O'Connor
- Ian O'Connor
- Jane O'Connor
- Mary-Anne O'Connor
- Mary-Frances O'Connor
- Nuala O'Connor
- Sharon O'Connor
- Sinéad O'Connor
- Tracy O'Connor
- Claire O'Dell
- Scott O'Dell
- James J. O'Donnell
- Jennifer O'Donnell
- Jodi O'Donnell
- Lawrence O'Donnell
- Lawrence O'Donnell Jr.
- Lisa O'Donnell
- Sharon O'Donnell
- Tom O'Donnell
- John O'Donohue
- Pat O'Donohue
- Zoe More O'Ferrall
- Katie O'Flynn
- Mark O'Flynn
- Olivia O'Flynn
- Daniel O'Grady
- Kristina O'Grady
- Andrew O'Hagan
- Sarah Robb O'Hagan
- Bill O'hanlon
- Kate O'Hara
- Mary O'Hara
- Maryanne O'Hara
- Mo O'Hara
- Nancy O'Hara
- Tracey O'Hara
- Denis O'Hare
- Sinéad O'Hart
- Jim O'Heir
- Dan O'Herlihy
- Eileen O'Higgins
- Trish O'Kane
- Alexandra O'Karma
- David O'Keefe
- Jac O'Keeffe