The banded killifish (Fundulus diaphanus), is a North American species of temperate freshwater killifish belonging to the Fundulus genus of the Fundulidae family. The natural geographic range extends from Newfoundland to South Carolina, and west to Minnesota. It occupies the Great Lakes drainages. The banded killifish is the only freshwater killifish found in the Northeastern United States, but can occasionally be found in brackish water.