Olney is a census-designated place and an unincorporated area in Montgomery County, Maryland. It is located in the north central part of the county, twenty miles (32 km) north of Washington, D.C. It was largely agricultural until the 1960s,

Olney is a census-designated place and an unincorporated area in Montgomery County, Maryland. It is located in the north central part of the county, twenty miles (32 km) north of Washington, D.C. It was largely agricultural until the 1960s, when growth of the Washington suburbs led to its conversion into a mostly residential area. As generally defined, Olney had a total population of 33,844 in the 2010 U.S. Census. In 2013 it was ranked #22 Money magazine's "top-earning towns" edition of "America's Best Places to Live."