Wilmette, IL has a population of 27,367 and is the 1,576th largest city in the United States. The population density is 5,065 per sq mi which is 2178% higher than the Illinois average and 5490% higher than the national average. The median age in Wilmette is 44 which is approximately 18% higher than the Illinois average of 37. In Wilmette, 71% of the population over 15 years of age are married, 81% speak English and 2% speak Spanish. 54% of Wilmette residents were born in Illinois, 27% were born out of state, 1% were born outside of the United States and 18% were foreign born.