Dogtooth Island is a landlocked fluvial island adjacent to the Mississippi River. Approximately 3 miles (4.9 km) long, it is part of Alexander County in the U.S. state of Illinois. The nearest community is Willard, Illinois. The patch of wetland, still called by courtesy an "island", is on the tip of Dogtooth Bend, a fluvial oxbow-peninsula formed by a meander of the Mississippi Rivber. Much of the Island has been placed in conservation easement for purposes of wetland reserve and floodplain restoration.

37°01′10″N 89°16′56″W / 37.01949°N 89.28230°W / 37.01949; -89.28230