Tallmadge is a city in eastern Summit County, Ohio, United States, with a small district in neighboring Portage County. It is a suburb of Akron a…Tallmadge is a city in eastern Summit County, Ohio, United States, with a small district in neighboring Portage County. It is a suburb of Akron and part of the Akron metropolitan area. The population was 18,394 at the 2020 census. Tallmadge was founded in 1807 and is the second-oldest city in Summit County, following Hudson, which was founded in 1799.