Farmington Hills is a city in Oakland County in the U.S. state of Michigan. A northwestern suburb of Detroit, Farmington Hills is located roughly …Farmington Hills is a city in Oakland County in the U.S. state of Michigan. A northwestern suburb of Detroit, Farmington Hills is located roughly 22 miles from downtown Detroit. As of the 2020 census, the city's population was 83,986, making it the second-largest community in Oakland County.