Fults Hill Prairie State Natural Area, also known as the Fults Hill Prairie Nature Preserve, is an Illinois Nature Preserve on 997 acres (403 ha) in Monroe County, Illinois, United States. A key feature of the preserve is a 532-acre (215 ha) hill prairie located on the east bluff of the Mississippi River overlooking the American Bottom near Fults, Illinois. The Fults Hill Prairie has been listed as a National Natural Landmark.