Buffalo, MN has a population of 15,927 and is the 2,687th largest city in the United States. The population density is 2,199 per sq mi which is 3454% higher than the Minnesota average and 2327% higher than the national average. The median age in Buffalo is 34 which is approximately 10% lower than the Minnesota average of 38. In Buffalo, 59% of the population over 15 years of age are married, 94% speak English and 3% speak Spanish. 77% of Buffalo residents were born in Minnesota, 19% were born out of state, 1% were born outside of the United States and 4% were foreign born.