Member Political Organisation
Gordon Oakes Rural District Councils Association
William O'Brien United Irish League
Tom O'Brien TUC
James O'Brien United Irish League
T.P. O'Connor United Irish League
Frank O'Donnell Irish Home Rule Confederation of Great Britain
John O'Donnell United Irish League
James O'Grady TUC
Sean O'Kelly Gaelic League
Hugh O'Neill 1922 Committee
Cranley Onslow 1922 Committee
Maurice Orbach Socialist Medical Association
Thomas Ormiston Cinematograph Exhibitors' Association
Lawrence Orr Orange Order
Ian Orr-Ewing Rural District Councils Association
Ian Orr-Ewing 1922 Committee
John Osborn 1922 Committee
Cyril Osborne Inter-Parliamentary Union for Peace and Arbitration
Eugene O'Sullivan Land and Labour Association
Idris Owen National Federation of Building Trades Employers