Westmont, IL has a population of 25,149 and is the 1,719th largest city in the United States. The population density is 5,031 per sq mi which is 2163% higher than the Illinois average and 5453% higher than the national average. The median age in Westmont is 42 which is approximately 12% higher than the Illinois average of 37. In Westmont, 57% of the population over 15 years of age are married, 78% speak English and 7% speak Spanish. 65% of Westmont residents were born in Illinois, 14% were born out of state, 1% were born outside of the United States and 20% were foreign born.