Stillwater River may refer to:

New Zealand

Stillwater River (New Zealand) The Stillwater River is a river in New Zealand, flowing into Caswell Sound, Fiordland. See also *List of rivers of New Zealand This is a list of all waterways named as rivers in New Zealand. A * Aan River * Acheron River (Canterbury) * ...

, on the South Island

United States

Stillwater River (Maine) The Stillwater River is an U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 22, 2011 side channel of the Penobscot River in Maine. From its source () in Old Town, the Stillwater runs ...

Stillwater River (Nashua River tributary) The Stillwater River is part of the Nashua River watershed. This river is part of the Massachusetts Water Resources Authority system that supplies drinking water to the greater Boston area. The Stillwater River rises in Princeton, Massachusetts, ...

, Massachusetts *

Stillwater River (Stillwater County, Montana) The Stillwater River is a tributary of the Yellowstone River. Approximately 70 miles (113 km) long, it runs through southern Montana in the United States. The Stillwater River has also been known as: the Itchkeppearja River, Rose River, ...

, a tributary of the Yellowstone River * Stillwater River (Flathead County, Montana), a tributary of the Whitefish River *

Stillwater River (Ohio) The Stillwater River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed May 19, 2011 tributary of the Great Miami River in western Ohio Ohio () is a state in the Midwestern region ...

Stillwater River (Rhode Island) The Stillwater River is a river in the U.S. state of Rhode Island. It flows approximately .U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed April 1, 2011 There are four dams along the riv ...