The Grant River is a 44-mile-long (71 km) tributary of the upper Mississippi River in southwestern Wisconsin in the United States. It flows for its entire length in Grant County. The city of Potosi is located near its mouth. Tributaries include Boice Creek, Rattlesnake Creek, Pigeon Creek, Blake Fork, Little Grant River, Borah Creek, and Rogers Branch. As part of the Driftless Area of Wisconsin, the river has a substantial valley.
The Army Corps of Engineers maintains the Grant River Recreation Area at the river's mouth. Camping, fishing and boating are the main attractions.
The river was named for an early trapper who lived on the river bank.
- U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map Archived 2012-03-29 at the Wayback Machine, accessed May 13, 2011
- Gannett, Henry (1905). The Origin of Certain Place Names in the United States. Govt. Print. Off. pp. 142.
- Grant River Recreation Area
- Wisconsin Dept. of Natural Resources - Grant and Platte Basins
- U.S. Geological Survey Geographic Names Information System: Grant River