| Big St. Martin Island | |
| Map: | Michigan |
| Coordinates: | 45.9683°N -84.6281°W[1] |
| Country: | United States |
| Country Admin Divisions Title: | State |
| Country Admin Divisions: | Michigan |
| Country1 Admin Divisions Title: | County |
| Country1 Admin Divisions: | Mackinac County |
| Country2 Admin Divisions Title: | Township |
| Country2 Admin Divisions: | St. Ignace Township |
Big St. Martin Island is an island in Mackinac County of the U.S. state of Michigan. It is located in St. Martin Bay, a bay of Lake Huron.[1]
Like other islands in and around the Mackinac Straits, Big St. Martin Island is believed to be sacred ground to local Native Americans. The island was privately owned as of 2010.[2]