High Force is a waterfall on the River Tees, near Middleton-in-Teesdale, Teesdale, England. The waterfall is within the North Pennines Area of Outstanding Natural Beauty (AONB) and the European Geopark. The whole of the River Tees plunges 70 feet (21 m) over a precipice in two stages. After heavy rainfall the river will also flow over the usually dry right-hand side channel, creating two falls. Very occasionally the river level will be high enough to flow over the central section of rock; the last recorded time this happened was in December 2015 after Storm Desmond. In harsh winters the falls have been known to freeze, creating cathedral-like ice formations.

The River Tees, in England, rises on the eastern slope of Cross Fell in the North Pennines and flows eastwards for 85 miles (137 km) to reach the North Sea in the North East of England. The modern day history of the river has been tied with the industries on Teesside in its lower reaches, where it has provided the means of import and export of goods to and from the North East England. The need for water further downstream also meant that reservoirs were built in the extreme upper reaches, such as Cow Green.