This article is about the Bass Islands of Lake Erie. For the Bass Islands (Îles du Bass) of French Polynesia, see Bass Islands (French Polynesia).

The Bass Islands are four islands of the Great Lakes, specifically Lake Erie.

The islands are called South Bass Island, Middle Bass Island, North Bass Island, and (the much smaller) Gibraltar Island. They are located in Ottawa County in the state of Ohio. Historically Middle Bass has also been called Ile de Fleurs and North Bass was known as Isle St. George.

South Bass Island is approximately 3.7 miles (6.0 km) long and 1.5 miles (2.4 km) wide and comprises 1,382 acres (5.6 km²). South Bass Island is approximately 3.0 miles (4.8 km) north of the nearest point on the mainland (Scott Point on Catawba Island) and approximately 10 air miles (16 km) NNE of Port Clinton, Ohio and 14 air miles (23 km) NNW of Sandusky, Ohio.

The village of Put-in-Bay is located on South Bass Island. It is a popular tourist stop during the summer. Perry's Victory and International Peace Memorial , including Perry's Monument, commemorating the Battle of Lake Erie is located on South Bass Island, near Put-In-Bay. The island is also the annual host of the Inter-Lake Yachting Association regatta, known as Bay Week.

Gibraltar Island is located in the middle of the crescent shaped bay, providing for an exceptionally well sheltered anchorage area.

At their closest points, Middle Bass Island is approximately 0.5 miles (0.8 km) north of South Bass Island and North Bass Island is approximately 1.0 miles (1.6 km) north of Middle Bass Island. The border between Ohio and Ontario is approximately 1.0 (1.6 km) miles north of North Bass Island.

As of late April, 2004, the State of Ohio now owns virtually all of North Bass Island, which it purchased from private owners. Plans for the future use of the island are not yet known.