Mount Vernon is a city located in Jefferson County Illinois. It is also the county seat of Jefferson County. With a 2020 population of 14,667, it is the 163rd largest city in Illinois and the 2350th largest city in the United States . Mount Vernon is currently declining at a rate of -0.19% annually and its population has decreased by -3.99% since the most recent census, which recorded a population of 15,277 in 2010. Mount Vernon reached it's highest population of 17,193 in 1980. Spanning over 15 miles, Mount Vernon has a population density of 1,006 people per square mile.
The average household income in Mount Vernon is $59,111 with a poverty rate of 22.22%. The median rental costs in recent years comes to $714 per month, and the median house value is $78,600. The median age in Mount Vernon is 38.6 years, 34.7 years for males, and 41.1 years for females.