Blackbird Creek (Delaware)

Blackbird Creek is a 16.9-mile-long (27.2 km) river in northern Delaware in the United States.

It rises in southern New Castle County, in several streams southwest of Blackbird, in the Blackbird State Forest. It flows northeast, in a highly meandering course, flowing into the north end of Delaware Bay approximately 0.25 miles (0.40 km) south of the mouth of the Appoquinimink River and approximately 2 miles (3.2 km) north of Taylors Bridge.

The watershed of the river is largely forested and rural. Near its mouth, it is surrounded by extensive salt marshes, with extensive populations of saltmarsh cordgrass (Spartina alterniflora) and common reed. The lower river upstream from Delaware State Highway 9 is protected as part of the Delaware National Estuarine Research Reserve, along with portions of the lower Appoquinimink.

The damming of this creek was the subject of the 1829 Supreme Court case that gave rise to the theory of the Dormant Commerce Clause.