Fennville is a city in Allegan County in the U.S. state of Michigan. The population was 1,745 at the 2020 census. Located on M-89 on the boundary between Manlius Township to the north and Clyde Township to the south, Fennville is located about 11 mi southeast of the city of Saugatuck and about 13 mi west-northwest of the city of Allegan. It is about 13 mi south of Holland, about 16 mi northeast of South Haven and roughly 40 mi miles southwest of Grand Rapids.