Westchester is a village located in Cook County, Illinois, within the United States. Situated as a western suburb of Chicago, it occupies a specific geographic position with coordinates at 41.8539 north latitude and 87.8836 west longitude. The community shares its western border with Du Page County, marking a distinct administrative boundary within the region. As a incorporated village, it functions as a residential and commercial hub for the greater Chicago metropolitan area.

The area was initially occupied by German farmers starting in the mid-19th century. In 1924, Samuel Insull purchased the land with plans to develop it into an English-style town, which influenced the naming of the town and most of its streets. Development was slowed by the Great Depression but stimulated by its role as the western terminal of Chicago's Garfield Park rapid transit line until that extension was removed in 1951.

Residential and retail development has consumed nearly all open land, leaving only the protected 85-acre Wolf Road Prairie as a significant natural feature. This prairie is noted as the largest black-soil prairie remnant east of the Mississippi River. The village also features the Westbrook Corporate Center, a complex of five 10-story towers constructed in 1986 and renovated in 1996, which has received multiple awards for office building excellence.

The community offers various recreational amenities through the Westchester Park District, including five golf courses within a short drive and several forest preserves. Residents utilize facilities such as the John J. Sinde Community Swimming Pool, dedicated in 1977, which features a 50-meter pool and water slide. The area also supports youth sports organizations, bowling alleys, and escape rooms, providing diverse leisure options for both residents and visitors.

The population was 16,892 at the 2020 census, with a median age of 48.3 years. The economy is supported by the Westbrook Corporate Center and various local employers, with median household income reported at $88,861. Transportation relies heavily on cars due to zoning provisions and the absence of current CTA Blue Line plans, though Pace Bus Service provides routes 301, 317, and 330 to the community.