Waukesha, WI has a population of 72,016 and is the 504th largest city in the United States. The population density is 2,823 per sq mi which is 3129% higher than the Wisconsin average and 3016% higher than the national average. The median age in Waukesha is 35 which is approximately 10% lower than the Wisconsin average of 39. In Waukesha, 54% of the population over 15 years of age are married, 87% speak English and 8% speak Spanish. 70% of Waukesha residents were born in Wisconsin, 21% were born out of state, 1% were born outside of the United States and 8% were foreign born.