Poolesville is a U.S. town in the western portion of Montgomery County, Maryland. The population was 5,742 at the 2020 United States Census. It is surrounded by the Montgomery County Agricultural Reserve, and is considered a distant bedroom community for commuters to Washington, D.C. The name of the town comes from the brothers John Poole Sr. and Joseph Poole Sr. who owned land and slaves in what is now Poolesville.