Forest Grove is a city in Washington County, Oregon, United States, west of Portland. Originally a small farm town, it is now primarily a bedroom suburb of Portland. Settled in the 1840s, the town was platted in 1850 and then incorporated in 1872, making it the first city in Washington County. The population was 21,083 at the 2010 census, an increase of 19.1 rom the 2000 census (17,708).