Pennsylvania - Role: Building
| Lea, Henry C., School of Practice |
| Leas, Benjamin B., House |
| Leaser, Frederick and Catherine, Farm |
| Leedom, David, Farm |
| Leesport Lock House |
| Lee Tire and Rubber Company |
| Lehigh Valley Railroad Headquarters Building |
| Lehigh Valley Silk Mills |
| Lehigh Valley Transit Station |
| Lehigh Water Gap Chain Bridge Toll House and East Bridge Abutment |
| Lehner Grain-and-Cider Mill and House |
| Leidy, Dr. Joseph, House |
| Leiper, Thomas, Estate |
| Lemington Elementary School |
| LeMoyne Crematory |
| Lemoyne, Dr. Julius, House |
| LeMoyne, F. Julius, House |
| Lenhart Farm |
| Lerch Tavern |
| Lesley, J. Peter, House |
| Letsche Elementary School |
| Levan Farm |
| Levering, William, School |
| Lewisburg Armory |
| Lewis, Evan, House |
| Lewistown Armory |
| Liberty Fire Company No. 5 |
| Liberty Hall |
| Liberty School No. 4, Friendship Building |
| Lightfoot Mill |
| Lightner, Isaac, House |
| Ligonier Armory |
| Lincoln Elementary School |
| Lincoln, Mordecai, House |
| Linden Avenue School |
| Linden Grove Pavilion |
| Linden House |
| Lindsey, Christiana, House |
| Lits Department Store |
| Littell, David, House |
| Little Jerusalem AME Church |
| Little, Moses, Tavern |
| Livingood House-Stryker Hospital |
| Llanerch Public School |
| Lloyd and Henry Warehouse |
| Lochiel Farm |
| Lock Ridge Furnance Complex |
| Locust Grove |
| Logan Demonstration School |
| Logan Furnace Mansion |
| Logan Mills Gristmill |
| Log House, Hiester House, and Market Annex |
| Loller Academy |
| Longfellow, Henry, School |
| Longfellow School |
| Long-Hawerter Mill |
| Longland |
| Long Meadow Farm |
| Longwell, David, House |
| Lord House |
| Lorraine Apartments |
| Loutellus Apartment Hotel |
| Lowell, James Russell, School |
| Lower Marsh Creek Presbyterian Church |
| Lower Merion Academy-Cynwyd Elementary School-Bala Cynwyd Junior High School Complex |
| Lower Swedish Cabin |
| Lowrie, Sen. Walter, House |
| Loyalhanna Lodge No. 275 |
| Ludlow, James R., School |
| Lukens Main Office Building |
| Lunn's Tavern |
| Lutheran Theological Seminary-Old Dorm |
| Lutz-Franklin School |
| Lutz, John F., Furniture Co. & Funerary |
| Luzerne County Courthouse |
| Luzerne County Fresh Air Camp |
| Luzerne Presbyterial Institute |
| Lycoming Rubber Company |
| Lynn Hall |
| Madison Elementary School |
| Madison, James, School |
| Main Building, U.S. Bureau of Mines |
| Main Library |
| Malden Inn |
| Malvern Hall |
| Manchester, Isaac, House |
| Manchester School No. 3 |
| Mann, William, School |
| Manor Street Elementary School |
| Mansfield |
| Mansfield Armory |
| Marine Barracks |
| Marine Corps Depot of Supplies, Schuykill Warehouse |
| Marine Corps Supply Activity |
| Markle Banking & Trust Company Building |
| Marshall, Humphry, House |
| Marshall, Humphry, House |
| Marshall, John, School |
| Marshall, Thomas, House |
| Marshallton Inn |
Data from United States Park Service and Wikidata
