High Force is a waterfall on the River Tees, near Middleton-in-Teesdale, Teesdale, County Durham, England. The waterfall is within the North Pennines Area of Outstanding Natural Beauty (AONB) and European Geopark.
Despite popular belief that it is the highest waterfall in England, at 21.5 metres (71 ft), others have a longer fall: Cautley Spout, in Cumbria's Howgill Fells, is almost 180 metres (590 ft) high, and Hardraw Force, in North Yorkshire, has an unbroken drop of 30 metres (98 ft); whilst underground, on the flanks of Ingleborough, Fell Beck falls an unbroken 96 metres (315 ft) down the Jib Tunnel of Gaping Gill Hole.
The whole of the River Tees plunges over a precipice (cliff edge which is almost vertical) in two stages. In former times flooding created two separate falls, but after the completion of Cow Green Reservoir in the upper Teesdale this seldom happens now. In harsh winters the falls would freeze, creating cathedral-like ice formations.