Heart Butte, MT has a population of 596 and is the 18,483rd largest city in the United States. The population density is 131 per sq mi which is 1812% higher than the Montana average and 44% higher than the national average. The median age in Heart Butte is 23 which is approximately 42% lower than the Montana average of 40. In Heart Butte, 43% of the population over 15 years of age are married, 86% speak English and 0% speak Spanish. 89% of Heart Butte residents were born in Montana, 8% were born out of state, 1% were born outside of the United States and 2% were foreign born.