Horicon Marsh
| Horicon National Wildlife Refuge/Horicon Marsh State Wildlife Area | |
|---|---|
IUCN category IV (habitat/species management area) | |
A boardwalk in the marsh | |
| Location | Dodge, Fond du Lac counties, Wisconsin, United States |
| Nearest city | Waupun, Wisconsin |
| Coordinates | 43°32′59″N 88°39′21″W / 43.5497141°N 88.6559380°W |
| Area | 21,400 acres (87 km2) |
| Established | 1941 |
| Governing body | U.S. Fish and Wildlife Service Wisconsin Department of Natural Resources |
| Website | Horicon Marsh National Wildlife Refuge |
| Designated | 12 April 1990 |
| Reference no. | 511 |
Horicon Marsh is a marsh located in northern Dodge and southern Fond du Lac counties of Wisconsin. It is the site of both a national and a state wildlife refuge.