The Bad River is a tributary of the Missouri River, approximately 110 mi (177 km) long, in central South Dakota in the United States.

It rises in southern Haakon County, approximately 15 mi (24 km) north of Cottonwood, and flows SE then ENE, passing Midland and Capa . It joins the Missouri at Fort Pierre.

The river basin is noted for deposits of manganese and fuller's earth.

See also

• List of South Dakota rivers