Mills River lies in the northwestern part of Henderson County, extending northeast to the Buncombe County border and southwest to the Transylvania County border. It is bordered to the northeast by the city of Asheville and the town of Fletcher.

The population was 6,802 at the 2010 census,[4] and was estimated to be 7,406 in 2019.[5] The town took its name from the nearby confluence of the Mills River and French Broad River.[6] It is part of the Asheville Metropolitan Statistical Area. It was incorporated into a town in June 2003. Sierra Nevada opened a brewery in Mills River in 2014.