Scar House Reservoir is the second of the three reservoirs in Upper Nidderdale, North Yorkshire, England, the others being Angram Reservoir and Gouthwaite Reservoir. Between them they attract around 150,000 visitors a year.

Angram and Scar House were built to supply water to the Bradford area of West Yorkshire. Water from here is transferred to Chellow Heights via the Nidd Aqueduct using only gravity and no pumping.

The dam contains over one million tonnes of masonry, it rises to 55 metres (180 ft) above the river and is almost 600 m (2,000 ft) long. It was completed in 1936. The dam height is 71 m (233 ft). The reservoir is fed almost exclusively from Angram Reservoir, which in turn is fed predominantly from the flanks of Great Whernside.