Pennsylvania - Significance region: Local
| Logan Furnace Mansion |
| Logan Mills Covered Bridge |
| Logan Mills Gristmill |
| Log House, Hiester House, and Market Annex |
| Loleta Recreation Area |
| Loller Academy |
| Longfellow, Henry, School |
| Longfellow School |
| Long-Hawerter Mill |
| Long Meadow Farm |
| Longue Vue Club and Golf Course |
| Longwell, David, House |
| Loutellus Apartment Hotel |
| Lovell Manufacturing Company |
| Lowell, James Russell, School |
| Lower Humbert Bridge |
| Lower Marsh Creek Presbyterian Church |
| Lower Merion Academy-Cynwyd Elementary School-Bala Cynwyd Junior High School Complex |
| Lower North Philadelphia Speculative Housing Historic District |
| Lowrie, Sen. Walter, House |
| Loyalhanna Lodge No. 275 |
| Ludlow, James R., School |
| Lukens Main Office Building |
| Lumberville Historic District |
| Lunn's Tavern |
| Lupfer, Israel and Samuel, Tannery Site and House |
| Lutz-Franklin School |
| Lutz, John F., Furniture Co. & Funerary |
| Luzerne County Courthouse |
| Luzerne Presbyterial Institute |
| Lycoming Rubber Company |
| Lynn Hall |
| Madison Elementary School |
| Madison, James, School |
| Main Library |
| Makefield Meeting |
| Malvern Hall |
| Manayunk Main Street Historic District |
| Manchester Historic District |
| Manchester, Isaac, House |
| Manchester School No. 3 |
| Manheim Borough Historic District |
| Mann, William, School |
| Manor Street Elementary School |
| Mansfield |
| Marcus Hook Plank House |
| Marianna Historic District |
| Marietta Historic District |
| Marine Corps Depot of Supplies, Schuykill Warehouse |
| Markle Banking & Trust Company Building |
| Marklesburg Historic District |
| Marlborough Village Historic District |
| Marshall, John, School |
| Marshall, Thomas, House |
| Marshallton Historic District |
| Marshallton Inn |
| Marsh Creek Advent Church |
| Martin, B. B., Tobacco Warehouse |
| Martin Farmstead |
| Martin, James, School |
| Martin Orthopedic School |
| Martin Tower |
| Mary B. Sharpe School |
| Mary Immaculate Seminary (MIS) |
| Mascot Roller Mills |
| Masonic Temple |
| Matlack, Enoch, House |
| Mauer, Dr. Joseph House |
| Mayer Building |
| Mayer, David M., House |
| Mayfair House |
| Mays, Blaney Covered Bridge |
| McAllister, Archibald, House |
| McAllister-Beaver House |
| McCalls Ferry Farm |
| McCallum Manor |
| McCleary Elementary School |
| McClelland-Grimes Farm |
| McClelland Homestead |
| McClenathan, J.C., Dr., House and Office |
| McClure, Alexander K., School |
| McCollum and Post Silk Mill |
| McConnell House |
| McConnellsburg Historic District |
| McCook Family Estate |
| McCoy-Shoemaker Farm |
| McDaniel, Delaplaine, School |
| McDowell Memorial Presbyterian Church |
| McFarlane, Andrew and Jennie, House |
| McGees Mills Covered Bridge |
| McGovern, Edward, Tobacco Warehouse |
| McIlvain, Francis, House |
| McKeesport National Bank |
| Meade, George, School |
| Meadville Downtown Historic District |
| Mechanicsburg Commercial Historic District |
| Mechanicsville School |
| Mechanicsville Village Historic District |
| Mecky, A., Company Building |
| Meehan, Thomas, School |
Data from United States Park Service and Wikidata
