St. Regis, MT has a population of 239 and is the 23,596th largest city in the United States. The population density is 279 per sq mi which is 4004% higher than the Montana average and 208% higher than the national average. The median age in St. Regis is 38 which is approximately 5% lower than the Montana average of 40. In St. Regis, 58% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 44% of St. Regis residents were born in Montana, 53% were born out of state, 4% were born outside of the United States and 0% were foreign born.