Brownstown Charter Township is a charter township in Wayne County in the U.S. state of Michigan. The population was 30,627 at the 2010 census. Brownstown was established in 1827, a decade prior to Michigan's Admission to the Union. Brownstown has three separate but connected segments; due to the incorporation of the cities of Flat Rock, Rockwood, and Woodhaven in the early 1960s.