Olney, Maryland

Olney, Maryland
Olney's St. John's Episcopal Church in 2013
Location of Olney in Maryland
Coordinates: 39°08′11″N 77°04′17″W / 39.13639°N 77.07139°W / 39.13639; -77.07139
Country United States
State Maryland
County Montgomery
Area
 • Total
16.22 sq mi (42.02 km2)
 • Land16.18 sq mi (41.91 km2)
 • Water0.042 sq mi (0.11 km2)
Elevation
499 ft (152 m)
Population
 (2020)
 • Total
35,820
 • Density2,213.6/sq mi (854.69/km2)
Time zoneUTC−5 (Eastern (EST))
 • Summer (DST)UTC−4 (EDT)
ZIP codes
20830, 20832, 20833
Area codes301, 240
FIPS code24-58900
GNIS feature ID2389620

Olney is a census-designated place and an unincorporated area in Montgomery County, Maryland, United States. It is located in the north central part of the county, thirteen miles (21 km) north of Washington, D.C.

Olney was largely agricultural until the 1960s, when growth of Washington, D.C.'s suburbs led to its conversion into a mostly residential area. It has a total population of 35,820 as of the 2020 United States census.