Eagle Creek State Park is a protected public recreation area in central Illinois along the shores of Lake Shelbyville. Encompassing 11,100 acres in Shelby County, it includes a broad stretch of lakeside landscape shaped by the reservoir and surrounding land. Managed within the Illinois state park system, it is also identified in state materials as Eagle Creek State Recreation Area. Its significance lies in its close connection to Lake Shelbyville and in its standing as one of the larger state park properties associated with the lake.