Massachusetts - Area of significance: Architecture
| Kensington Park Historic District |
| Kenwyn Apartments |
| Kessler, William F., House |
| Keyes, Amos, House |
| Keyes, Jonathan, Sr. House |
| Kidder-Sargent-McCrehan House |
| Kilmer Street Fire Station |
| Kilsyth Terrace |
| Kimball, C. Henry, House |
| Kimball, Solomon, House |
| Kimball, W.W., House |
| King Caesar House |
| King House |
| Kingman, Gardner J., House |
| King Philip Mills |
| Kingsbury House |
| Kingsbury-Whitaker House |
| King's Chapel |
| Kingsley, Chester, House |
| Kingsley House |
| Kingston Center Historic District |
| Kinney, A., House |
| Kirkland Place Historic District |
| Kistler House |
| Kittredge, Alvah, House |
| Kittredge Mansion |
| Knapp, Job, House |
| Knapp, Seth, Jr. House |
| Knight, Elisha, Homestead |
| Knight, R. A.-Eugene Lacount House |
| Knollwood |
| Knowles, Lucius, House |
| Knowlton Hat Factory |
| Kugel, Peter, House |
| Kunhardt, George, Estate |
| LaCroix-Mosher House |
| Laflin-Phelps Homestead |
| Lakeside Cemetery Chapel |
| Lake, Stanley, House |
| Lake Street Fire Station |
| LAMARTINE (shipwreck) |
| Lambert, Thomas, House |
| Lamson, Newton, House |
| Lamson, Rufus, House |
| Lancaster Industrial School for Girls |
| Lancaster Mills |
| Landlord Fowler Tavern |
| Lane, Anthony, House |
| Lane, David, House |
| Lane, Fitz Henry (formerly known as Fitz Hugh), House |
| Lane, Job, House |
| Langmaid Building |
| Langmaid Terrace |
| Larches, The |
| Larch Farm |
| Larchmont |
| LaRochelle, Napoleon, Two-Family House |
| Larrabee's Brick Block |
| Larson, Swan, Three-Decker |
| Lasell Neighborhood Historic District |
| Laurel Hall |
| Lawrence Academy |
| Lawrence Avenue Historic District |
| Lawrence Light Guard Armory |
| Lawrence Model Lodging Houses |
| Lawrence, Phineas, House |
| Lawrence Street Cemetery |
| Lawrence, William, House |
| Lawson Tower |
| Lawton Place Historic District |
| Leather District |
| Leavitt-Hovey House |
| Lechmere Point Corporation Houses |
| Lee, Jeremiah, House |
| Lee Lower Main Street Historic District |
| Lee Station |
| Legg, John, House |
| Leland, Deacon William, House |
| Lennon, Edward J., House |
| Lenox Academy |
| Lenox High School |
| Lenox Library |
| Lenox Railroad Station |
| Lenox Street Apartments Historic District |
| Lenox Village Historic District |
| Leominster High School |
| Leonard, Capt. Charles, House |
| Leonard, James, House |
| Leonard School |
| Leonard. Shaw & Dean Shoe Factory |
| Levenson, Morris, Three-Decker |
| Leverett Center Historic District |
| Lewis, Charles D., House |
| Lewis House |
| L.H. Hamel Leather Company Historic District |
| Libby, Nelson F., House |
| Liberty Hall |
| Liberty Tree District |
| Lincoln, Ambrose, Jr., House |
| Lincoln, Asa, House |
Data from United States Park Service and Wikidata
