William O'Brien (2 October 1852 – 25 February 1928) was an Irish
nationalist, journalist, agrarian agitator, social revolutionary, politician, party leader, newspaper publisher, author and Member of Parliament (MP) in the
House of Commons of the
United Kingdom of Great Britain and Ireland. He was particularly associated with the campaigns for land reform in Ireland during the late 19th and early 20th centuries as well as his conciliatory approach to attaining
Irish Home Rule.