Wisconsin Rapids, WI. Online Offers. Wisconsin Rapids is a city in and the county seat of Wood County, Wisconsin, United States. The population was 18,435 at the 2000 census. According to the 2010 census, the Wisconsin Rapids micropolitan area was home to 54,362 people. The city also forms one of the core areas of the United States Census Bureau's Marshfield-Wisconsin Rapids Micropolitan Statistical Area, which includes all of Wood County (2000 population: 82,433).