Mauvoisin Dam is a concrete variable radius arch dam across the Val de Bagnes on the Dranse de Bagnes stream, in the canton of Valais, Switzerland. Initial construction on the dam commenced in 1951 and was completed in 1957, with the reservoir filling by 1958. In 1991, the dam was raised to increase the capacity of the reservoir for winter storage. The dam's primary purpose is hydroelectric power generation.

An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthening the structure as it pushes into its foundation or abutments. An arch dam is most suitable for narrow canyons or gorges with steep walls of stable rock to support the structure and stresses. Since they are thinner than any other dam type, they require much less construction material, making them economical and practical in remote areas.