Nassawango Creek (locally /næsəˈwɒŋɡoʊ/ or /næsəˈwæŋɡoʊ/) is a stream in the U.S. state of Maryland; it is the largest tributary of the Pocomoke River, located on the Delmarva Peninsula.

Older variations on the same name include Nassanongo, Naseongo, Nassiongo, and Nassiungo, meaning "[ground] between [the streams]".

[1] Early English records have it as Askimenokonson Creek, after a Native settlement near its headwaters (askimenokonson roughly approximating a local Algonquian word meaning "stony place where they pick early [straw]berries").

Large portions of its drainage lie within the Pocomoke River State Forest and The Nature Conservancy's Nassawango Creek Preserve.

[4] Nassawango Creek and its tributaries were once dammed in several places for mills; one dam site, became an early industrial blast furnace operation, where bog iron ore was smelted to make pig iron at Furnacetown during the first half of the 19th century.