Pennsylvania - Significance region: Local
| Koerner, Henry, House |
| Kolb, Dielman, Homestead |
| Kramer Covered Bridge No. 113 |
| Krauskap, Henry, House, and Store |
| Kreider Shoe Manufacturing Company |
| Kreigbaum Covered Bridge |
| Krepps Covered Bridge |
| Kulp, Isaac, Farm |
| Kunkel Building |
| Kurtz, T. M., House |
| Kutz Mill |
| Kutztown 1892 Public School Building |
| Kutztown Silk Mill |
| La Blanche Apartments |
| Lacey, Gen. John, Homestead |
| Lackawanna Avenue Commercial Historic District |
| Lackawanna Mills and Scranton Button Historic District |
| Lady Washington Inn |
| Lahr Farm |
| Lairdsville Covered Bridge |
| Lake City School |
| Lancaster County Courthouse |
| Lancaster County House of Employment |
| Lancaster Crematorium |
| Lancaster Trust Company |
| Landis Shoe Company Building |
| Landreth, David, School |
| Langhorne Historic District |
| Langhorne Library |
| Langhorne Manor School |
| Langley High School |
| Lansdale Silk Hosiery Company-Interstate Hosiery Mills, Inc. |
| Lansdowne Park Historic District |
| Lansdowne Theatre |
| Lansford Historic District |
| Lapp Log House |
| Larimer School |
| Larkin-Belber Building |
| Latimer School |
| Laughlin, Hugh, House |
| Laurel Hill Furnace |
| Laurel-Rex Fire Company House |
| Lawndale School |
| Lawrence County Courthouse |
| Lawrence Public School |
| Lawrenceville Historic District |
| Leader Theater |
| Lea, Henry C., School of Practice |
| Leas, Benjamin B., House |
| Leaser, Frederick and Catherine, Farm |
| Leatherman Covered Bridge |
| Leedom, David, Farm |
| Leesport Lock House |
| Lee Tire and Rubber Company |
| Legislative Route 1 Sycamore Allee |
| 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 |
| Leibhart, Byrd, Site (36YO170) |
| Leibhart, Oscar, Site (36YO9) |
| Leiby, Jacob, Farm |
| Lemington Elementary School |
| Lemont Historic District |
| Lenhart Farm |
| Lerch Tavern |
| Letsche Elementary School |
| Levan Farm |
| Levering, William, School |
| Lewisburg Historic District |
| Lewis, Evan, House |
| Liberty Fire Company No. 5 |
| Liberty Hall |
| Liberty School No. 4, Friendship Building |
| Lightner, Isaac, House |
| Ligonier Historic District |
| Lincoln Elementary School |
| Lincoln, Mordecai, House |
| Linden Avenue School |
| Linden Grove Pavilion |
| Linden Hall at Saint James Park |
| Linden Hall Historic District |
| Linden House |
| Lindsey, Christiana, House |
| Lionville Historic District |
| Lititz Moravian Historic District |
| Littell, David, House |
| Little Jerusalem AME Church |
| Little, Moses, Tavern |
| Livingood House-Stryker Hospital |
| Llanerch Public School |
| Lloyd and Henry Warehouse |
| Llyswen Historic District |
| Lobb's Cemetery and Yohogania County Courthouse Site |
| Lochiel Farm |
| Lock Ridge Furnance Complex |
| Locust Grove |
| Locust Grove Cemetery |
| Logan Demonstration School |
Data from United States Park Service and Wikidata
