Authors
- Gordon H. Orians
- Origene
- Benedetta Origo 1
- Iris Origo
- Oriole
- Professor Orla-Jensen
- Arthur E. Orlaff
- Orlan
- Franko B. Orlan
- Matthew J. Orland
- Paulo Orlandini
- Massimo Orlando
- Christopher Orlebar 1
- F. St. J. Orlebar
- Lena Orlin
- David E. Orlinsky
- Laszlo Orloci 1
- P. Orman
- Suze Orman
- Tony Orman
- Bryony J. Orme
- Eve Orme
- John David Orme 1
- Nicholas Orme
- William Orme
- Graham J. Orme-Bannister
- Alick Ormerod
- Eleanor A. Ormerod
- Elizabeth Ormerod 1
- G. Wareing Ormerod 1
- George Ormerod
- J. Ormerod
- Jan Ormerod 2
- Roger Ormerod
- Sarah Ormerod 1
- Stephen Ormerod
- Ian Ormes
- Rosalind Ormiston
- Thomas Lane Ormiston
- Brande Ormond
- John Ormond
- Richard Ormond 1
- Edward Ormondroyd
- W.M. Ormrod
- Barbara Stephanie Ormsby
- Frank Ormsby
- Ierne Ormsby 1
- M.T.M. Ormsby
- Dean Ornish
- Robert Ornstein
- G.H. Orpen
- Neil Orpen
- T.H. Orpen
- William Orpen 1
- C.C. Orr
- D.W. Orr
- David B. Orr 1
- David R. Orr
- David W. Orr
- J.B. Orr
- James Orr
- Lord Boyd Orr
- M.A. Orr
- Monro S. Orr
- Robert Low Orr
- Robin A. Orr
- Stewart Orr
- Wendy Orr
- William I. Orr
- John Orr Ewing
- Ian Orr-Ewing
- LORD ORR-EWING
- R. Orrell
- John Orrery
- Leslie Orrey
- David Orrick
- Geoffrey R. Orrin
- Bruce Orriss
- Rolande Orry
- Dod Orsborne
- G. Orshan
- Adolfo Orsi 1
- Luigi Orsini
- Paul Ortegat
- Dennis Ortenburger 1
- Dennis E. Ortenburger
- H.P. Orth
- Angelika Orthaus
- R. Ortigues
- Antonio Dominguez Ortiz
- Dominguez Ortiz
- Elisabeth Lambert Ortiz
- Charles Ortleb
- Erwin Ortmann
- Jon Ortner
- Sherry B. Ortner
- Donald.J Ortnner
- Alexandra Ortolja-Baird
- Anthony Orton
- D.A. Orton