Anchor Bay is a freshwater bay forming the northern region of Lake St. Clair in the U.S. state of Michigan. It generally encompasses the waters north of a line between Huron Point (part of the Lake St. Clair Metro Park Beach, not to be confused with Port Huron) and the Middle Channel of the St. Clair River (which enters Lake St. Clair between Dickinson Island and Harsens Island). It covers over 90 square miles (230 km2) and a depth of from 1 to 11 feet (0.30 to 3.35 m), which is unusually shallow for its immense size.