Oswald O'Brien (6 April 1928 – 10 March 1997) was a British and European Labour Co-operative politician.
He was born Oswald O'Brien into the Darlington family of a disabled First World War soldier and mill worker mother in 1928.
From St Mary's Catholic Grammar School he went to Fircroft College, Birmingham and St Cuthbert's Society in the University of Durham, during which he served as President of the Durham Union, after World War II service in the Royal Navy which he volunteered for lying about his age by one year (aged 14) to relieve economic pressure on his family.
He was a teacher at Durham University, Director of Studies of the Co-operative College, Workplace Director of Alcohol Concern, member of Commission of Industrial Relations, Workers' Educational Association, and European and International Consultant on workers rights, economics and security.
In the general election held less than two months later, he lost the seat by a margin of 3,438 votes to the Conservative candidate Michael Fallon, who had been his rival in the by-election.