Mequon, WI has a population of 23,663 and is the 1,843rd largest city in the United States. The population density is 511 per sq mi which is 485% higher than the Wisconsin average and 464% higher than the national average. The median age in Mequon is 49 which is approximately 26% higher than the Wisconsin average of 39. In Mequon, 73% of the population over 15 years of age are married, 90% speak English and 2% speak Spanish. 62% of Mequon residents were born in Wisconsin, 29% were born out of state, 1% were born outside of the United States and 8% were foreign born.