The Denis Rankin Round is a long distance hill running challenge around the Mourne Mountains in County Down, Northern Ireland. The route is a circuit of over 90 kilometres, with a total climb of over 6,500 metres. The Round must be completed within 24 hours to be considered a success.
The record times are 13:20 by Shane Lynch and 19:12 by Aoife Mundow.
Much of the route runs through the Mourne Mountains Area of Outstanding Natural Beauty; the highest summit in both Ulster and Northern Ireland (Slieve Donard) is included. The Round must be completed either in the order below, or in the reverse order.