Markham is a city located in Illinois. With a 2020 population of 12,222, it is the 197th largest city in Illinois and the 2679th largest city in the United States. Markham is currently declining at a rate of -0.80% annually and its population has decreased by -2.29% since the most recent census, which recorded a population of 12,508 in 2010. Markham reached it's highest population of 15,987 in 1970. Spanning over 5 miles, Markham has a population density of 2,261 people per square mile.
The average household income in Markham is $52,880 with a poverty rate of 24.83%. The median rental costs in recent years comes to $1,266 per month, and the median house value is $85,900. The median age in Markham is 37.2 years, 30.2 years for males, and 38.9 years for females. For every 100 females there are 83.1 males.