Organizations: O
O'Neill's Dramatic Company
Oak Hall
Oak Tree Press
Oakham Grammar School
Oakland High School
Obelisk Press
Oberlin College
Oberlin College, Young Ladies Institution
Oberon Books
Oblates
Observer Books
Obstetrical Association of Midwives
Obstetrical Society
Obstetrical Society of London
Occupy
Ocean Accident and Guarantee Corporation Limited
OCLC
Octagon Theatre
October Club
Octopus Publishing Group
Oddfellows
Oddy and J. Goodwin
Odham Press
ODTAA
Office International d'Hygiène Publique
Office of Facts and Figures
Office of the United Nations High Commissioner for Refugees
Office of War Information
Office of Works, Edinburgh
Officer Cadet Training Unit
Official IRA
Ogilvy, Benson, and Mather
Ogwugwu Afor
Oireachtas
Ojai Festival
Old Bridewell Prison
Old Canterbury Arms
Old City Publishing
Old Fire Station Arts Centre
Old Fruitmarket
Old People's Welfare Association
Old Vic
Old Vic Company
Old Watercolour Society
Older Feminists Network
Oldham Repertory Company
Oldham's Companion Book Club
Oliphant, Anderson and Ferrier
Olive Schreiner Letters Project
Ollendorff