As of the 2020 United States Census, Naperville had a population of approximately 149,540, making it the fourth most populous city in Illinois. The city experienced explosive growth from the 1980s through the early 2000s, though the population has stabilized into a slow, steady growth pattern in recent years.
Naperville is known for its highly educated population. Over 70% of adults hold a bachelor's degree or higher, a figure significantly above the national average. This correlates with high median household incomes, which regularly exceed $135,000.
The ethnic and racial composition of Naperville has become increasingly diverse over the past few decades. While a majority of the population identifies as White (approx. 65%), there is a substantial and growing Asian community (approx. 20%), alongside Hispanic/Latino (approx. 6%) and Black or African American (approx. 5%) populations. A variety of languages are spoken at home, reflecting the global talent drawn to the city's tech corridor. The community is home to diverse religious groups, with numerous churches, temples, and mosques spread throughout the city.