Montgomery County is the most populous county in the state of Maryland. As of the 2020 U.S. Census, the county's population was 1,062,061, increasing by 9.3% from the 2010 Census.

It is by far one of the most ethnically and culturally diverse counties in the United States; 4 of the 10 most culturally diverse cities and towns in the U.S. are in Montgomery County: Gaithersburg, ranking 2nd; Germantown, ranking 3rd; Silver Spring, ranking 4th; and Rockville, ranking 9th.

Montgomery County has 19 municipalities:

Barnesville 

Brookeville

Chevy Chase, Town of  

Chevy Chase View

Chevy Chase Village

Chevy Chase, Village of, Section 3 

Chevy Chase, Village of, Section 5 

Gaithersburg 

Garrett Park 

Glen Echo 

Kensington 

Laytonsville

Martin's Additions

North Chevy Chase 

Poolesville 

Rockville 

Somerset

Takoma Park and 

Washington Grove

The oldest municipality in Montgomery County is Brookeville, incorporated in 1808, followed by:

Rockville (1860)

Poolesville (1867)

Gaithersburg (1878) 

Barnesville (1888)

Takoma Park (1890) 

Laytonsville (1892) 

Kensington (1894) 

Garrett Park (1898) 

Glen Echo (1904) 

Somerset (1906)

Chevy Chase Village (1910)

Town of Chevy Chase (1918) 

Washington Grove (1937)

Village of Chevy Chase, Sections 3 and 5 (1982) 

Martin's Additions (1985) 

Chevy Chase View (1993)

North Chevy Chase (1996)