The Harbor Island National Wildlife Refuge is a 695-acre (281 ha) horseshoe-shaped island and National Wildlife Refuge in Potagannissing Bay north of Drummond Island in the U.S. state of Michigan. The island was acquired in 1983 by the United States Fish and Wildlife Service from its previous owner, The Nature Conservancy, and set aside as a refuge. It is located in Drummond Township, in Chippewa County.