The surname Dunlap or Dunlop is of Scottish origin. Two-Thirds of Dunlaps or Dunlops are found in county Antrim. It is a common name in Ayrshire, deriving from the lands of Dunlop in the district of Cunningham.

The first to bear the name was Willhelmus de Dunlop in 1260. The placename is dun lapach "muddy hill'. The name was common in Kintyre after the plantation of lowlanders there in the 17th century.

Dunlops from Arran settled in North Antrim in the early 17th century, and a Bryce Dunlop received lands between Ballycastle and Ballintoy from Sir Randall MacDonnell, marrying Christian Stewart, daughter of John Stewart of the Island of Bute.