Repeal was a demand by Irish nationalist leader Daniel O'Connell for the repeal of the 1801 Act of Union which had merged the Kingdoms of Great Britain and Ireland to form the United Kingdom of Great Britain and Ireland. He wanted to see the re-establishment of the Kingdom of Ireland as a separate legal entity, with its own parliament and government, sharing only a joint monarch with Britain. Ireland's kingdom was to be equal to Britain; a similar equality would exist with both their parliaments. His repeal campaign failed, though he achieved Catholic Emancipation.

In contrast, later Irish nationalist leaders like Charles Stewart Parnell demanded merely Home Rule, which involved the creation of a subsidiary parliament in Ireland, with Ireland remaining part of the United Kingdom. Ireland's parliament would only be a devolved local administration, inferior to Westminster in terms of powers, status and influence. It could also be abolished by an Act of the British parliament.

Arthur Griffith, original leader of Sinn Féin, was also opposed to the Act of Union and looked for two independent countries with a dual monarachy. His proposal was simply to regard the Act of Union as invalid and to act as it did not exist. This policy did not survive the takeover of his party by Irish republicans in 1917.