Beloit, WI has a population of 36,812 and is the 1,140th largest city in the United States. The population density is 2,124 per sq mi which is 2329% higher than the Wisconsin average and 2244% higher than the national average. The median age in Beloit is 35 which is approximately 12% lower than the Wisconsin average of 39. In Beloit, 48% of the population over 15 years of age are married, 82% speak English and 15% speak Spanish. 59% of Beloit residents were born in Wisconsin, 31% were born out of state, 1% were born outside of the United States and 9% were foreign born.