Illinois - Criteria: B (person)
| Tree Studio Building and Annexes |
| Trumbull, Lyman, House |
| Ulery, Eli, House |
| Union House |
| University of Illinois Astronomical Observatory |
| Warfield, William S., House |
| Warner, Seth, House |
| Warren, Edward Kirk, House and Garage |
| Washburne, Elihu Benjamin, House |
| Weir, William S., Jr., House |
| Wells-Barnett, Ida B., House |
| West Bluff Historic District |
| West Walnut Street Historic District |
| Weyerhaeuser House |
| Whitney, William, House |
| Willard, Frances, House |
| Williams, Dr. Daniel Hale, House |
| Williams, James Robert, House |
| Wilson, Judge Isaac, House |
| Wood, John, Mansion |
| Woodlawn Cemetery |
| Woodlawn Farm |
| Wright, Frank Lloyd, House and Studio |
| YMCA Hotel |
| Young, Joshua P., House |
Data from United States Park Service and Wikidata
