Three Rivers, MI has a population of 7,743 and is the 4,817th largest city in the United States. The population density is 1,427 per sq mi which is 1314% higher than the Michigan average and 1475% higher than the national average. The median age in Three Rivers is 31 which is approximately 21% lower than the Michigan average of 40. In Three Rivers, 50% of the population over 15 years of age are married, 95% speak English and 4% speak Spanish. 70% of Three Rivers residents were born in Michigan, 27% were born out of state, 1% were born outside of the United States and 2% were foreign born.