Lexington is a suburban town in Middlesex County, Massachusetts, United States, located 10 miles (16 km) from Downtown Boston. The population was 34,454 as of the 2020 census. The area was originally inhabited by Native Americans, and was first settled by Europeans in 1641 as a farming community. Lexington is well known as the site of the first shots of the American Revolutionary War, in the Battle of Lexington on April 19, 1775, where the "Shot heard 'round the world" took place. It is home to Minute Man National Historical Park.

Middlesex County is a county located in the Commonwealth of Massachusetts, United States. As of the 2020 census, the population was 1,632,002, making it the most populous county in both Massachusetts and New England and the 22nd most populous county in the United States. Middlesex County is one of two U.S. counties to be amongst the top 25 counties with the highest household income and the 25 most populated counties. It is included in the Census Bureau's Boston–Cambridge–Newton, MA–NH Metropolitan Statistical Area. As part of the 2020 United States census, the Commonwealth's mean center of population for that year was geo-centered in Middlesex County, in the town of Natick.