The Mispillion River is a river flowing to Delaware Bay in southern Delaware in the United States. It is approximately long and drains an area of on the Atlantic Coastal Plain.
It rises in northern Sussex County, approximately southwest of Milford, and flows generally east-northeastwardly, defining the boundary between Sussex and Kent counties; it passes through the center of Milford on its course to its mouth at Delaware Bay, northwest of Cape Henlopen. The lower of the river are considered by the U.S. Army Corps of Engineers to be navigable.
A boardwalk known as the Mispillion Riverwalk follows the river in Milford. , an effort was underway to preserve a greenway along the river upstream and downstream of Milford.
Variant names and spellings
According to the Geographic Names Information System, the Mispillion River has also been known historically as: