Montgomery County, Maryland

Montgomery County, Maryland
County of Montgomery
Clockwise: Downtown Bethesda, Spring Street in Silver Spring, Billy Goat B Trail, rural Darnestown, Rockville town center, Great Falls on the Potomac River
Nickname: 
"MoCo"
Motto: 
French: Gardez Bien (English: Watch Well)
Location in the U.S. state of Maryland
Coordinates: 39°08′11″N 77°12′15″W / 39.13638°N 77.20424°W / 39.13638; -77.20424
Country United States
State Maryland
SeatRockville
Largest communityGermantown
FoundedSeptember 6, 1776
Named afterRichard Montgomery
Government
  ExecutiveMarc Elrich (D)
Area
  Total
506.91 sq mi (1,312.89 km2)
  Land493.11 sq mi (1,277.15 km2)
  Water13.80 sq mi (35.74 km2)
Population
 (2024)
  Total
1,082,273
  Density2,153.80/sq mi (831.59/km2)
DemonymsMontgomery Countyan, MoCoite
Gross Domestic Product
  Total$106.7 billion (2022)
Time zoneUTC−05:00 (Eastern [EST])
  Summer (DST)UTC−04:00 (EDT)
ZIP Codes
20812–20918
Area codes
Congressional districts4th, 6th, 8th
Websitewww.montgomerycountymd.gov

Montgomery County is the most populous county in the U.S. state of Maryland. As of the 2020 United States census, the county's population was 1,062,061, increasing by 9.3% from 2010. The county seat is Rockville, and Germantown is the most populous place in the county. The county is adjoined to Washington, D.C., the nation's capital, and is part of the Washington metropolitan area and the Washington–Baltimore combined statistical area. Most of the county's residents live in Silver Spring, Bethesda, Germantown, and the incorporated cities of Rockville and Gaithersburg.

The average household income in Montgomery County is the 20th-highest among U.S. counties as of 2020.

The county has the highest percentage (29.2%) of residents over 25 years of age who hold post-graduate degrees. Like other counties in the Washington metropolitan area, the county has several U.S. government offices, scientific research and learning centers, and business campuses.