Fort Walsh, National historic site and former North-West Mounted Police fort in Cypress Hills, Saskatchewan, Canada

Fort Walsh is a reconstructed North-West Mounted Police post and National Historic Site in the Cypress Hills of southwestern Saskatchewan, Canada. Its buildings, including barracks, stables and officers' quarters, were reconstructed in the 1940s to breed horses for the Royal Canadian Mounted Police and the Musical Ride. The site also includes the former townsite, cemeteries and a whisky trading post.

Fort Walsh was built in June 1875 by Inspector James Morrow Walsh and B Troop of the North-West Mounted Police, created after the Cypress Hills Massacre of 1873 to curb the illegal whisky trade and protect the US border. It served as NWMP headquarters from 1878 to 1882, and on 25 September 1877 three Assiniboine chiefs signed adhesion to Treaty 4 there. Closed and dismantled in 1883, it was designated a National Historic Site in 1924.

Assiniboine chiefs Man Who Takes the Coat, Long Lodge and Lean Man signed adhesion to Treaty 4 at Fort Walsh on 25 September 1877. In summer, guides in 1880s dress lead tours of the reconstructed buildings and the former townsite, telling of Inspector James Walsh's dealings with Sitting Bull's Lakotas.

Fort Walsh lies within Cypress Hills Interprovincial Park, southwest of Maple Creek, Saskatchewan, and is reached by road; no public transport serves the site. The grounds, former townsite, cemeteries and whisky trading post are explored on foot, and in summer guides in 1880s costume lead tours of the furnished buildings. Since 28 September 2004 the site has formed part of the Cypress Hills dark-sky preserve, so night visits reward those who stay after dark.

From 1942 to 1968, the site ran a horse breeding program that supplied animals for the Royal Canadian Mounted Police Musical Ride. The horses raised here were selected for their ability to move in precise formations during public performances.