Delaware - Significance region: Local
| Sutton, Thomas, House |
| Talley, William, House |
| Tatnall, Joseph, House |
| Taylor's Bridge School |
| Teddy's Tavern |
| Tharp House |
| Thomas, David W., House |
| Thomas' Methodist Episcopal Chapel |
| Thompson's Loss and Gain Site |
| Thorne, Parson, Mansion |
| Todd's Chapel |
| Torbert Street Livery Stables |
| Townsend, Henry, Building |
| Trinity Episcopal Church |
| Trinity Methodist Episcopal Church |
| Tunnell-West House |
| Tyn Head Court |
| U.S. Post Office, Courthouse, and Customhouse |
| Vail, A. M., House |
| Vandegrift, J., House |
| Vandyke-Heath House |
| Vansant, John C., House |
| Voshell, John M., House |
| Walker, J., Farm |
| Walker, R., Barn |
| Walnut Farm |
| Walnut Green School |
| Walnut Lane |
| Warren's Mill |
| Water Witch Steam Fire Engine Company No. 5 |
| Wawaset Park Historic District |
| Weldin, Lewis, House |
| Wesley M.E. Church |
| West 9th Street Commercial Historic District |
| Weston |
| West Potato House |
| West Woods Methodist Episcopal Church |
| Wheel of Fortune |
| White Clay Creek Presbyterian Church |
| White Hall |
| White-Warren Tenant House |
| Wilgus Site |
| Williams House |
| Williams, James, House |
| Williams, J. K., House |
| Wilmington Rail Viaduct |
| Wilmington Savings Fund Society |
| Wilmington Trust Company Bank |
| Wilmington YMCA |
| Wilson, Edward R., House |
| Windsor |
| Woman's Club of Newport |
| Wooddale Bridge |
| Woodley, Jonathan, House |
| Woodside |
| Woodside Methodist Episcopal Church |
| Woodstock |
| Woodward Houses |
| Woolworth, F. W., Company Building |
| Wright-Carry House |
| Wright House |
| Wright Potato House |
| Wyoming Historic District |
| Wyoming Railroad Station |
| Young, William, House |
| Zion African Methodist Episcopal Church |
Data from United States Park Service and Wikidata
