Marseilles is a city located in Illinois. With a 2020 population of 4,772, it is the 340th largest city in Illinois and the 4895th largest city in the United States . Marseilles is currently declining at a rate of -0.65% annually and its population has decreased by -6.32% since the most recent census, which recorded a population of 5,094 in 2010. Marseilles reached it's highest population of 5,109 in 2010. Spanning over 10 miles, Marseilles has a population density of 526 people per square mile.
The average household income in Marseilles is $64,443 with a poverty rate of 15.27%. The median rental costs in recent years comes to $949 per month, and the median house value is $108,400. The median age in Marseilles is 40.9 years, 40 years for males, and 42 years for females.