James O'Brien
John O'Brien
Michael O'Brien
Richard Ocock
Daniel O'Connor
Patrick O'Day
Michael O'Dea
James Oddie
James O'Donnell
Patrick O'Donoghue
John Ogier
James O'Grady
John O'Meara
John O'Neil
Richard O'Neil
Thomas O'Neill
George Osborne
John O'Shannessy
John O'Toole
William Otway
John Owens
Francis Oxley
