Batavia, IL has a population of 26,413 and is the 1,630th largest city in the United States. The population density is 2,522 per sq mi which is 1034% higher than the Illinois average and 2684% higher than the national average. The median age in Batavia is 41 which is approximately 9% higher than the Illinois average of 37. In Batavia, 63% of the population over 15 years of age are married, 92% speak English and 5% speak Spanish. 74% of Batavia residents were born in Illinois, 20% were born out of state, 1% were born outside of the United States and 5% were foreign born.