As of the census of 2000, there were 15,688 people, 7,632 households, and 3,480 families residing in the village. The population density was 6,480.8 people per square mile (2,503.0/km²). There were 7,981 housing units at an average density of 3,297.0/sq mi (1,273.3/km²). The racial makeup of the village was 56.14% White, 31.18% African American, 0.15% Native American, 6.83% Asian, 0.07% Pacific Islander, 2.80% from other races, and 2.82% from two or more races. Hispanic or Latino of any race were 7.84% of the population, including 5.6% Mexican.
The top five non-African American, non-Hispanic ethnicities reported in Forest Park as of the 2000 census were German (15.9%), Irish (14.6%), Italian (8.1%), English (5.9%) and Polish (5.3%).
There were 7,632 households out of which 21.9% had children under the age of 18 living with them, 28.9% were married couples living together, 12.8% had a female householder with no husband present, and 54.4% were non-families. 45.3% of all households were made up of individuals and 9.9% had someone living alone who was 65 years of age or older. The average household size was 2.03 and the average family size was 2.94.
In the village the population was spread out with 19.8% under the age of 18, 7.9% from 18 to 24, 39.8% from 25 to 44, 20.3% from 45 to 64, and 12.2% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 90.2 males. For every 100 females age 18 and over, there were 86.9 males.
The median income for a household in the village was $44,103, and the median income for a family was $52,611. Males had a median income of $39,402 versus $32,255 for females. The per capita income for the village was $26,045. About 6.3% of families and 7.0% of the population were below the poverty line, including 7.5% of those under age 18 and 6.7% of those age 65 or over.