Pennsylvania - Area of significance: Architecture
| Johnson-Hatfield Tavern |
| Johnson, John, House |
| Johnson, Nicholas, Mill |
| Johnston's Tavern |
| Jones and Laughlin Steel Company Building |
| Jones, Benjamin F., Cottage |
| Jones, B. F., Memorial Library |
| Jones, James, House |
| Jones, John Paul, Junior High School |
| Juniata Iron Works |
| Juvenile and Domestic Branches of the Municipal Court |
| Kagerise Store and House |
| Kane Armory |
| Kane, Thomas L., Memorial Chapel |
| Karolcik Building |
| Kastner, Jacob, Loghouse |
| Kauffman Mill |
| Kaufmann's Department Store Warehouse |
| Keefe-Mumbower Mill |
| Keim Homestead |
| Keith House-Washington's Headquarters |
| Keller, Jacob, Farm |
| Kelly, Amos, House |
| Kemmerer House |
| Kenderdine Mill Complex |
| Kennedy, Francis W., House |
| Kennedy Mansion |
| Kennedy, Robert, Memorial Presbyterian Church |
| Kennett Square Historic District |
| Kensington Branch of the Philadelphia YWCA |
| Kensington High School for Girls |
| Kent, Thomas, Jr., Farm |
| Ker-Feal |
| Kerr, Thomas R., Dr., House and Office |
| Keswick Theatre |
| Key, Francis Scott, School |
| Keystone Building |
| Keystone Hook and Ladder Company |
| Keystone Hotel |
| Keystone Mill |
| Kimberton Village Historic District |
| Kinbawn |
| Kinder's Mill |
| King of Prussia Inn |
| Kingston Armory |
| Kingston House |
| Kinsey, John L., School |
| Kirkbride, Eliza Butler, School |
| Kirk Johnson Building |
| Kirkland Station |
| Kirks Mills Historic District |
| Kirk, William, House |
| Kise Mill Bridge Historic District |
| Kissling Farm |
| Kistler Residence |
| Kitchen, William, House |
| Kittanning Passenger Station and Freight Depot |
| Klein Meetinghouse |
| Knabb-Bieber Mill |
| Knapp Farm |
| Knauer, John, House and Mill |
| Knauss, Heinrich, House |
| Knickerbocker Historic District |
| Knipe-Johnson Farm |
| Knipe-Moore-Rupp Farm |
| Knisley, Dr., Covered Bridge |
| Knorr-Bare Farm |
| Knowlton |
| Knoxville Junior High School |
| Knurr Log House |
| Kolb, Dielman, Homestead |
| Kooser State Park Family Cabin District |
| Krauskap, Henry, House, and Store |
| Kreider Shoe Manufacturing Company |
| Kulp, Isaac, Farm |
| Kunkel Building |
| Kurtz, T. M., House |
| Kutz Mill |
| Kutztown 1892 Public School Building |
| La Blanche Apartments |
| Lacawac |
| Lacey, Gen. John, Homestead |
| Lackawanna Avenue Commercial Historic District |
| Lahr Farm |
| Lake City School |
| Lancaster Armory |
| Lancaster City Historic District |
| Lancaster County Courthouse |
| Lancaster County House of Employment |
| Lancaster Crematorium |
| Lancaster Historic District |
| Lancaster Trust Company |
| Lancaster Watch Company |
| Landis Homestead |
| Landreth, David, School |
| Land Title Building |
| Lane House |
| Langhorne Historic District |
| Langhorne Library |
| Langhorne Manor School |
Data from United States Park Service and Wikidata
