North Louth was a parliamentary constituency in Ireland, which returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected on a system of first-past-the-post, from 1885 to 1918. Prior to the 1885 general election and after the dissolution of Parliament in 1918 the area was part of the Louth constituency.

This constituency comprised the northern part of County Louth. The seat was defined under the Redistribution of Seats Act 1885 as comprising the baronies of Louth, Lower Dundalk and Upper Dundalk, and that part of the barony of Ardee contained within the parishes of Killany and Louth.