Mouse Island is a seven acre[1] private island located in Lake Erie off the northern tip of Catawba Point in Ottawa County, Ohio, United States, near the city of Sandusky (41°35′28″N 82°49′59″W / 41.59111°N 82.83306°W / 41.59111; -82.83306).

The Hayes family built two small cabins, a hand ferry to the shore, a tennis court and supplied the island with running water.

The Hayes family owned the property until 1966 as none of the former president's grandchildren remained in the area.

Remains of the structures can still be found on the island today – including the native stone chimneys of the summer cabins as well as part of the foundation.

A limestone reef between the island and shoreline presents a safety hazard for watercraft that draw more than 3 feet.