Newaygo County is a county in the U.S. state of Michigan. As of the 2020 United States Census, the population was 49,978. The county seat is White Cloud. The county was created in 1840, and was organized in 1851. It was either named for an Ojibwe leader who signed the Treaty of Saginaw in 1819 or for an Algonquian word meaning "much water".

Hardy Dam is an earth-filled embankment dam and powerplant complex on the Muskegon River in Big Prairie Township, Newaygo County, Michigan. At the time of its completion, it was the largest earthen dam in North America east of the Mississippi. Its impoundment forms a lake with over 50 miles of shoreline. The dam impounds a reservoir with a surface area of 4,000 acres and its power plant has an installed capacity of 31.5 MW.