The Big Bay Sloop is the name given to the unidentified remains of a sunken sloop in Lake Superior located off the coast of Madeline Island in La Pointe, Wisconsin, United States.

The site was added to the National Register of Historic Places on January 14, 2009.

[2] Additionally, it is a designated National Marine Protected Area.

[3] The wreck was discovered east of Big Bay State Park in the 1990s.

Uncertainty about the identity of the vessel is due to the lack of documentation of small craft on the Great Lakes.