The Cypress Hills Massacre was a massacre which occurred on June 1, 1873 in the Cypress Hills region of Battle Creek, Saskatchewan, involving a group of American wolf hunters or "wolfers", American and Canadian whiskey traders, Metis freighters and a camp of Nakoda (or Assiniboine) people.

A large number of horses had been stolen from the wolfers just across the Montana border. Angry at the loss of their horses, the wolfers attempted to track the horse thieves into Canada, but soon lost their trail. Instead, the wolfers arrived in the Battle Creek valley where the trading posts operated by Abel Farwell and Moses Solomon were located opposite a camp of some 200 to 300 Nakoda people. Tensions were already somewhat elevated, alcohol had been flowing freely on all sides and a misunderstanding over a missing horse led to a mixed group of wolfers, whiskey traders and Metis freighters opening fire on the Nakoda camp, resulting in 23 confirmed Nakoda deaths and the death of one wolfer, Ed LeGrace. Both trading posts were subsequently abandoned and burned.

This incident outraged Canadians, who wanted Americans to respect their sovereignty, however, western Canada was threatened and then Prime Minister Sir John A. MacDonald was convinced to pass a bill to create the North West Mounted Police. Fort Walsh, Saskatchewan served as the NWMP headquarters from 1878 until 1883. All of the "wolfers" were arrested and tried but none were ever convicted.

Part of the site of the Cypress Hills Massacre has been preserved at Fort Walsh National Historic Site, along with reconstructions of Farwell's and Solomon's trading posts.