The Dewey Marsh is a state wildlife area in Portage County, Wisconsin, United States.

The Dewey Marsh is located in central Wisconsin approximately five to ten miles north of Stevens Point (Lat: 44° 38' 33.6", Lon: -89° 33' 40.6") in the center of the town of Dewey.

The Dewey Marsh began its early days as a hunting and fishing trading post with the local Native Americans.

[1] The Dewey Marsh was later purchased by the Wisconsin Department of Natural Resources to preserve its wetland heritage.

[2] The Dewey Marsh suffered a great fire in 1974, which burned in the bogs until 1976.