Gaithersburg , officially the
City of Gaithersburg, is a city located in
Montgomery County,
Maryland. At the time of the
2010 census, Gaithersburg had a population of 59,933, making it the fourth largest incorporated city in the state, behind
Baltimore,
Frederick, and
Rockville. Gaithersburg is located to the northwest of
Washington, D.C., and is considered a suburb and a primary city within the
Washington–Arlington–Alexandria, DC–VA–MD–WV Metropolitan Statistical Area. Gaithersburg was incorporated as a city in 1878.