Forest Grove is a city in Washington County, Oregon, United States, 25 miles west of Portland. Originally a small farm town, it is now primarily a commuter town in the Portland metro area. Settled in the 1840s, the town was platted in 1850, 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% over the 2000 figure.