Louisiana - Criteria: C (architecture/engineering)
| Jackson Historic District |
| Jackson House |
| Jackson Street Historic District |
| Jacobs, Walter B. |
| Jaenke, F. R., House |
| James, T. L., House |
| Janin Store |
| Jefferson, Joseph, House |
| Jennings Carnegie Public Library |
| Jennings Post Office |
| Joffrion House |
| John Hancock Building |
| Johnson House |
| Jones, Henry, Cottage |
| Jones House |
| Jones House |
| Jones, John Carroll, House |
| Jones, Wade H., Sr., House |
| Julia Street Row |
| Jung Hotel |
| Kansas City Southern Depot |
| Kansas City Southern Railroad Bridge, Cross Bayou |
| Kateland |
| Katie Plantation House |
| Keachi Baptist Church |
| Keachi Presbyterian Church |
| Keachi Store |
| Keachi United Methodist Church |
| Keegan House |
| Keegan House |
| Kell House |
| Kenilworth Plantation House |
| Kent Plantation House |
| Kerner House |
| Key-Mize House |
| Kidd-Davis House |
| Killarney |
| Killgore House |
| Kings Highway Christian Church |
| Kirby-Adam House |
| Kirby House |
| Kleinpeter House |
| Kleinpeter, John and Amelia Sharp, House |
| Knight Cabin |
| Knox Building |
| Kress Building |
| LaBarre House |
| Labatut |
| LaBranche Plantation Dependency |
| Labyche-Estorge House |
| Lafayette Hardware Store |
| Lafitte's Blacksmith Shop |
| Lafourche Parish Courthouse |
| Lake Charles City Hall, Old |
| Lake Charles Historic District |
| Lake Providence Historic District |
| Lake Providence Residential Street Historic District |
| Lakeside |
| Lakewood |
| LaLanne, Dominique, House and Store |
| Lamartina Building |
| Lambert House |
| Landry Plantation House |
| Landry Tomb |
| Lane Plantation House |
| Laran, Jean Marie, House |
| Latiolais, Alexandre, House |
| LaTour, Alexis, House |
| Laura Plantation |
| Laurel Hill |
| Laurel Valley Sugar Plantation |
| LeBeau House and Kitchen |
| LeBeuf Plantation House |
| LeBlanc House |
| LeCarpentier-Beauregard-Keyes House |
| Lecompte High School |
| Ledet House |
| Leeds Iron Foundry |
| Lefort House |
| LeJeune House |
| Lemann Store |
| Lemoine, Thomas A., House |
| Lemoine, Thomas A., House |
| Les Chenes Verts |
| Levert-St. John Bridge |
| Le Vieux Presbytere |
| Lewis House |
| Liberty Lodge No. 123, F & A M |
| Lincoln, George, House |
| Line Avenue School |
| Linwood |
| Linwood Plantation Manager's House |
| Little Texas |
| Live Oak |
| Live Oaks Plantation |
| Livingston Parish Courthouse, Old |
| Lobell, Adam, House |
| Logtown Plantation |
| Lone Pine |
| Long, George Parker, House |
Data from United States Park Service and Wikidata
