Brookfield, WI has a population of 37,991 and is the 1,095th largest city in the United States. The population density is 1,393 per sq mi which is 1493% higher than the Wisconsin average and 1437% higher than the national average. The median age in Brookfield is 47 which is approximately 19% higher than the Wisconsin average of 39. In Brookfield, 72% of the population over 15 years of age are married, 89% speak English and 2% speak Spanish. 68% of Brookfield residents were born in Wisconsin, 23% were born out of state, 1% were born outside of the United States and 9% were foreign born.