Thompson Falls Dam is a dam in Sanders County, Montana, in the northwestern part of the state.

A complex of four hydropower dams stand on the Clark Fork River in downtown Thompson Falls, Montana:

• Main Channel Dam (National Inventory of Dams ID MT00224), 54 feet (16 m) high
• Dry Channel Dam (MT83013), 38 feet (12 m) high
• Intake Dam A (MT83014), 53 feet (16 m) high
• Intake Dam B (MT83015), 110 feet (34 m) high

Operations here began in 1915 with original construction on a set of natural falls. Today, the four dams together impound an upstream reservoir, with a water storage capacity of 8,300 acre-feet (10,200,000 m³), and a seven-unit hydroelectric generation capacity of 94 megawatts.^[1]

Montana Power Company originally built the dam, PPL Corporation purchased it in 1997 and sold it to NorthWestern Corporation in 2014. The island between the dams contains a public park with hiking trails, picnic tables, and scenic overlooks.^[2] The site and adjacent buildings comprise the Thompson Falls Hydroelectric Dam Historic District, on the National Register of Historic Places.