Brookeville is a town in Montgomery County, Maryland, United States, located 20 km (12 mi) north of Washington, D.C., and 2 km (1.2 mi) north of Olney. Brookeville was settled by Quakers late in the 18th century and was formally incorporated as a town in 1808. Historically part of the local agricultural industry, since the 1950s Brookeville has developed rapidly into a suburban community of Washington, D.C. following the construction of the Georgia Avenue toll road. The population was 134 at the 2010 census.
Brookeville is notable as the "United States Capital for a Day" during the War of 1812, when British troops burned Washington D.C., and President James Madison sought refuge in Brookeville on August 26, 1814. During the American Civil War, Brookeville, along with nearby Sandy Spring, was a stop on the Underground Railroad.
The United States Postal Service (USPS) defines a larger area as Brookeville than what falls within the town boundaries. This includes areas extending to the Patuxent River and the Howard County border, and including the small hamlets of Sunshine and Brighton. Reddy Branch Stream Valley Park surrounds the Town of Brookeville, with the creek flowing west to east towards the Patuxent. Other parks and recreational areas include Rachel Carson Conservation Park, Patuxent River State Park, and the Triadelphia Reservoir.