Crestwood is a village in Cook County, Illinois, United States. The population was 10,950 at the 2010 census. Crestwood has been cited as a success story by proponents of low taxes and minimal government, but In April 2009, the Chicago Tribune revealed that Crestwood's low taxes were due to illegally saving money on its water bills by secretly supplementing its drinking water from a well that was contaminated with toxic chemicals.