Westmont is a village in DuPage County, Illinois, United States. Located in the southeastern portion of DuPage County, Westmont is a community of 5.03 square miles in area with a 2020 population of 24,429. It is a southwest suburb of Chicago.

U.S. Route 34 (US 34) is an east–west United States highway that runs for 1,122 miles (1,806 km) from north-central Colorado to the western suburbs of Chicago. Through Rocky Mountain National Park it is known as the Trail Ridge Road where it reaches elevation 12,183 feet (3,713 m), making one of the highest paved through highways in the United States. The highway's western terminus is Granby, Colorado at US 40. Its eastern terminus is in Berwyn, Illinois at Illinois Route 43 and Historic US 66.