Chignecto Bay is an inlet of the Bay of Fundy located between the Canadian provinces of New Brunswick and Nova Scotia and separated from the waters of the Northumberland Strait by the Isthmus of Chignecto. It is a unit within the greater Gulf of Maine Watershed. Chignecto Bay forms the northeastern part of the Bay of Fundy which splits at Cape Chignecto and is delineated on the New Brunswick side by Martin Head.