North Fermanagh was a UK Parliament constituency in Ireland which returned one Member of Parliament from 1885 to 1922, using the first past the post electoral system.

This county constituency comprised the northern part of County Fermanagh. The seat was defined under the Redistribution of Seats Act 1885 as comprising the baronies of Lurg, Magheraboy, and Tirkenny. The seat was unchanged under the Redistribution of Seats (Ireland) Act 1918.

Prior to the 1885 United Kingdom general election the area was part of the Fermanagh constituency. After the dissolution of Parliament in 1922 the constituency was incorporated in the new seat of Fermanagh and Tyrone

The constituency was a marginal one compared to many other seats in Northern Ireland. The Unionist candidate won in 1918, but Sinn Féin only polled 532 fewer votes.

Sinn Féin contested the general election of 1918 on the platform that instead of taking up any seats they won in the United Kingdom Parliament, they would establish a revolutionary assembly in Dublin. In republican theory every MP elected in Ireland was a potential Deputy to this assembly. In practice only the Sinn Féin members accepted the offer.

The revolutionary First Dáil assembled on 21 January 1919 and last met on 10 May 1921. The First Dáil, according to a resolution passed on 10 May 1921, was formally dissolved on the assembling of the Second Dáil. This took place on 16 August 1921.

In 1921 Sinn Féin decided to use the UK authorised elections for the Northern Ireland House of Commons and the House of Commons of Southern Ireland as a poll for the Irish Republic's Second Dáil. This area, in republican theory, was incorporated in an eight-member Dáil constituency of Fermanagh and Tyrone.