Indiana - Significance region: Local
| Judie, James A., House |
| Judson Building |
| Julian-Clark House |
| Jump, Dr. Samuel Vaughn, House |
| Junction Railroad Depot |
| Kamm and Schellinger Brewery |
| Keilman, Francis P. House |
| Keip, John, House |
| Kelham, Edward, House |
| Kelley-Fredrickson House and Office Building |
| Kellum, Noah and Hannah Hadley, House |
| Kendallville Downtown Historic District |
| Kendrick-Baldwin House (Cass County Memorial Home) Additional Documentation) |
| Kennedy-Hoffa House |
| Kensington Boulevard Historic District |
| Keplinger, Harry A., House |
| Kerr, John G., Company |
| Keyser Township School 8 |
| Kimbrough, Emily, Historic District |
| Kimmell Park |
| King-Dennis Farm |
| Kingsbury-Doak Farmhouse |
| Kintner House Hotel |
| Kintner-Withers House |
| Kirby Historic District |
| Kirklin Public Library |
| Kirkwood Park Historic District |
| Kirshbaum, Raphael, Building |
| Kitselman, Alva, House |
| Kixmiller's Store |
| Kline, John and Minerva, Farm |
| Knights of Columbus Building |
| Knights of Columbus-Indiana Club |
| Knights of Pythias Building and Theatre |
| Knights of Pythias Lodge |
| Knightstown, Old, and Glen Cove Cemeteries |
| Knox County Poor Asylum |
| Koerting, William and Helen, House |
| Koester/Patburg House |
| Kokomo City Building |
| Kokomo Courthouse Square Historic District |
| Kokomo High School and Memorial Gymnasium |
| Koontz, John F. and Malissa, House |
| Kosciusko County Jail |
| Kresge-Groth Building |
| Kuebler-Artes Building |
| Kuehn, August, House |
| Kuhn, Charles, House |
| Ladywood Estates |
| LaFontaine Historic District |
| La Grange County Courthouse |
| Lake County Sheriff's House and Jail |
| Lake County Tuberculosis Sanatorium Nurses Home and Superintendent's House |
| Lake Ditch Bridge |
| Lake Erie and Western Depot Historic District |
| Lakeside Historic District |
| Lakeville High School |
| Lamb's Creek Bridge |
| Lancaster Covered Bridge |
| Landers, Franklin-Black and Adams Farm |
| Landing, The, Historic District |
| LaSalle Annex |
| LaSalle Hotel |
| La Salle Street Bridge |
| Lassen Hotel |
| Laurel and Prospect District |
| Lauter, H., Company Complex |
| Lawton, Chauncey N., House |
| Learner Building |
| Lebanon Courthouse Square Historic District |
| Leeper Park |
| Leeper, Samuel, Jr., House |
| Leesburg Historic District |
| Legg House |
| Lehmback, Charles, Farmstead |
| Leich, Charles, and Company |
| Leive, Parks and Stapp Opera House |
| Leland Hotel |
| Lemmon's Church and Cemetery |
| Lenhart Farmhouse |
| Lentz House (Hotel Sheller) |
| Lerner Theatre |
| Levey, Louis, Mansion |
| Lewis, Thomas J., House |
| Liberty Baptist Church |
| Liberty Courthouse Square Historic District |
| Liberty Residential Historic District |
| Liberty Township Schoolhouse No. 2 |
| Ligonier Historic District |
| Lime Lake - Lake Gage Channel and Bridge |
| Lincoln Heights Historic District |
| Lincoln Park School |
| Lincoln Pioneer Village |
| Lincolnshire Historic District |
| Lincoln Street Historic District |
| Linden Depot |
| Lindenwood Cemetery |
| Lindley, Thomas Elwood, House |
| Linton Commercial Historic District |
| Linton Public Library |
Data from United States Park Service and Wikidata
