The All-for-Ireland League (AFIL) was an Irish, Munster-based political party (1909–1918). Founded by William O'Brien MP, it generated a new national movement to achieve agreement between the different parties concerned on the historically difficult aim of Home Rule for the whole of Ireland. The AFIL established itself as a separate non-sectarian party in the House of Commons of the United Kingdom of Great Britain and Ireland, binding a group of independent nationalists MPs to pursue a broader concept of Irish nationalism, a consensus of political brotherhood and reconciliation among all Irishmen, primarily to win Unionist consent to an All-Ireland parliamentary settlement.

William O'Brien 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.