Masinasin is a former community in Alberta, Canada within the County of Warner No. 5. It is located 1 km (0.62 mi) off Highway 501 on Range Road 133, approximately 31 km (19 mi) east of the Town of Milk River and 18 km (11 mi) north of the Canada–US border and Writing-on-Stone Provincial Park. All that remains of the former community is a small alternative school with baseball diamonds and the overgrown Pioneer Cemetery, approximately 3 km (1.9 mi) to the southeast on Highway 500.