Markham is a suburban city in Cook County, Illinois, United States. The population was 12,508 at the 2010 census.
Markham is located at 41°35′51″N 87°41′30″W / 41.59750°N 87.69167°W / 41.59750; -87.69167 (41.597467, -87.691570).
According to the 2010 census, Markham has a total area of 5.31 square miles (13.75 km), all land.
As of the 2000 census, there were 12,620 people, 3,842 households, and 3,119 families residing in the city. The population density was 2,420.6 people per square mile (935.2/km²). There were 4,019 housing units at an average density of 770.9 per square mile (297.8/km²). The racial makeup of the city was 17.30% White, 78.86% African American, 0.16% Native American, 0.59% Asian, 0.02% Pacific Islander, 1.61% from other races, and 1.46% from two or more races. Hispanic or Latino of any race were 3.14% of the population.
The top three non-African American ancestries reported in Markham as of the 2000 census were Irish (5.5%), German (5.1%) and Polish (3.1%).
There were 3,842 households out of which 33.9% had children under the age of 18 living with them, 43.6% were married couples living together, 30.3% had a female householder with no husband present, and 18.8% were non-families. 15.3% of all households were made up of individuals and 6.3% had someone living alone who was 65 years of age or older. The average household size was 3.28 and the average family size was 3.61.
In the city, the population was spread out with 31.4% under the age of 18, 9.5% from 18 to 24, 25.8% from 25 to 44, 21.4% from 45 to 64, and 11.9% who were 65 years of age or older. The median age was 33 years. For every 100 females, there were 86.7 males. For every 100 females age 18 and over, there were 81.0 males.
The median income for a household in the city was $41,592, and the median income for a family was $44,149. Males had a median income of $37,281 versus $27,723 for females. The per capita income for the city was $14,870. About 13.9% of families and 16.9% of the population were below the poverty line, including 23.9% of those under age 18 and 11.4% of those age 65 or over.