Marblehead is an unincorporated community in Adams County, Illinois, United States, just south of Quincy.

Illinois State Route 57 is the main auxiliary route through the town and travels north to the business district of Quincy or south to Interstate 72 (near Hannibal, Missouri).

The community is part of the Quincy, IL–MO Micropolitan Statistical Area.

A temporary (and satirically named) "Lake Marblehead" was formed when the flood plain flooded.

This Adams County, Illinois location article is a stub.