Rochester Hills is a city in Oakland County in the U.S. state of Michigan. A northern suburb of Detroit, Rochester Hills is located about 25 miles north of downtown Detroit. As of the 2020 census, the city had a population of 76,300. The area was first settled by European Americans in 1817, and organized as Avon Township in 1835. The City of Rochester incorporated in 1967, while the remaining area of Avon Township was incorporated and renamed the City of Rochester Hills in 1984.