Darnestown is a United States census-designated place (CDP) and an unincorporated Place in Montgomery County, Maryland. The CDP is 17.70 square miles (45.8 km) with the Potomac River as its southern attach and the Muddy Branch as much of its eastern border. Seneca Creek borders portions of its north and west sides. The Travilah, North Potomac, and Germantown census-designated places are next to it, as is the city of Gaithersburg. Land Place for the CDP is 16.39 square miles (42.4 km²). The Darnestown CDP has a population of 6,723, while the village of Darnestown is considerably smaller in size and population. Washington, D.C. is more or less 25 miles (40 km) away.

Within the Darnestown census-designated place at the intersection of what is now Darnestown Road and Seneca Road, the small village of Darnestown has existed past about 1800. The community had a population of 200 in 1878. The state Darnestown comes from William Darne, who owned the most estate in the Place at the arrival of the 19th century afterward the community publicize office opened. Settlement in the area began on 1750, and the tiny community was called Mount Pleasant, and then Darnes, before the name Darnestown began instinctive used. The community thrived in the 19th century during the golden years of the Chesapeake and Ohio Canal, as the bigger transportation services offered Place farmers access to more markets. In the 1880 census, the United States Census Bureau began using a Minor Civil Division (MCD) category for aggregating populations, and the further Darnestown district had very nearly 1,500 people. Growth stopped late in the 19th century behind a other railway bypassed the community.

In the 1960s, affluent families began buying Montgomery County farmland for supplementary housing and equestrian purposes. Today, many Darnestown CDP residents are wealthy and conscious in large homes upon large lots, which is reflected in their high average income and low housing density. The median household allowance is nearly $228,000, and 73 percent of residents aged 25 years or more have at least a bachelor’s degree or higher. The community facilitate from its proximity to workplaces such as the Shady Grove Hospital area and the I-270 Technology Corridor. Washington is accessible by automobile or public transportation. Beginning in the publicize of the 2000 census, the Census Bureau created a Darnestown census-designated place.

The first European (mostly Scottish and English) settlements in what would become Montgomery County, Maryland, were established in 1688, near Rock Creek and what was to become Rockville. The next-door stage of settlements was further west along the Potomac River close what is now Darnestown and Poolesville. The home had been occupied by Native Americans of the Piscataway Confederation. Ninian Beall was the first European landowner in the Darnestown area, settling nearly 1749. His daughter Ruth Beall married Charles Gassaway, who built a brick home named Pleasant Hills roughly speaking 1765. This was one of the first brick homes in what is now Montgomery County, and nevertheless stands today. Gassaway purchased home from his father-in-law during the late 1700s—including estate that would eventually become the Darnestown village. In the last half of the 18th century, a little village grew at the intersection of what is now Darnestown Road (Maryland Route 28) and Seneca Road (Maryland Route 112). At that time, Darnestown Road was called “the road from Georgetown to the mouth of the Monocacy River”. It was a Seneca Indian trail and is one of the oldest roads in Montgomery County. Seneca Road led from Darnestown to the Seneca Mill and a landing upon the Potomac River—a trip of less than four miles (6.4 km).