Ellis Mounds, near Marysville, Ohio, is a Native American archaeological site of three earthen mounds aligned east to west on a low ridgeline in a farm field. Generally attributed to Hopewellian peoples, it likely dates somewhere between 300 B.C. and A.D. 600. Its significance lies in the possibility of revealing aspects of everyday life that are less well understood than Hopewell burial practices, since research has often centered on larger ceremonial sites. Because it stands outside the main Hopewell heartland to the south, the site may also shed light on how Hopewell influence spread across the region. It was listed on the National Register of Historic Places in 1974.