The Southeastern Wisconsin Till Plains is an ecoregion in southeastern Wisconsin and northeastern Illinois in the United States. It is a Level III ecoregion in the classification system of the United States Environmental Protection Agency (EPA), where it is designated as ecoregion number 53. The ecoregion represents a transition between the hardwood forests and oak savannas to the west and the tallgrass prairie ecoregions to the south; it is today mostly covered by cropland.