Iowa - Significance region: Local
| Kenny Farmstead Archeological District |
| Kent Union Chapel and Cemetery |
| Keokuk County Courthouse |
| Keokuk Union Depot |
| Keokuk Young Women's Christian Association Building |
| Kerndt G., and Brothers Elevator and Warehouses, No. 11, No.12 and No. 13 |
| Kerndt, G., & Brothers Office Block |
| Kidder, Zephaniah, House |
| Kiene, Albert, House |
| Kimball-Stevenson House |
| Kimballton Commercial District |
| Kimballton West 2nd-West 3rd Street Residential District |
| Kingman Place Historic District |
| King Tower Historic District |
| Kirchner, Philip and Anna Parrish, Log House |
| Kirkham, Francis M., House |
| Kirkpatrick, Robert Round Barn |
| Kirk, The |
| Klindt, George, House |
| Klindt, Henry, House |
| Klinsky Farmstead Historic District |
| Klondike Hotel |
| Klose, Dr. William H. and Mae R., House |
| Knott, Adams R., Frederick L. and Martha (Taylor), House |
| Knott, Dr. Van Buren, House |
| Knotts, Nellie and Thomas, House |
| Koch Drug Store |
| Koch, Hans M., House |
| Koelman, Philipus J. and Cornelia, House |
| Koenig Building |
| Koester, Nicholas, Building |
| Koren Library |
| Kreinbring Phillips 66 Gas Station |
| Kromer Flats |
| Kucheman Building |
| Kuhnen, Nicholas J., House |
| Kurtz, Glenn and Nell, Lustron Home and Garage |
| Kurtz House |
| Kvindherred Lutheran Church, School and Cemetery |
| Kyte, John and Mary Jane, Farmstead District |
| Ladora Savings Bank |
| Lagomarcino-Grupe Company |
| Lake City Community Memorial Building |
| Lake City Public Library |
| Lake City Water Standpipe |
| Lake, John, House |
| Lakeside Ballroom |
| Lamb, Lafayette, House |
| Lamm-Pollmiller Farmstead District |
| Lancaster School |
| Lane, Samuel M., House |
| Lange, August H. J. and Justena, Farmstead Historic District |
| Langworthy Historic District |
| Lansing Main Street Historic District |
| Lansing Stone School |
| La Porte City Station |
| LaPorte City Town Hall and Fire Station |
| Larsen, Chris, House |
| Larsen, Jens T., House |
| Lattner Auditorium Building |
| Laurens Carnegie Free Library |
| Lee, Captain Daniel S. and Fannie L. (Brooks), House |
| Leeds Junior High School |
| Leith, Doctor Alexander R. (A.R.) and Louisa J., House |
| Le Mars Central High School |
| Le Mars Downtown Commercial Historic District |
| Le Mars Public Library |
| Lenox Hotel |
| Lerch, Gustov C., House |
| Lesinger Block |
| Lewis Hotel |
| Lewis, Judge W.H. and Emma, Historic District |
| Lewis System Armored Car and Detective Service Building |
| Lexington, The |
| Liberty Building |
| Lincoln Elementary School |
| Lincoln-Fairview Historic District |
| Lincoln Highway-Buttrick's Creek Abandoned Segment |
| Lincoln Highway-Buttrick's Creek to Grand Junction Segment |
| Lincoln Highway-Grand Junction Segment |
| Lincoln Highway-Little Beaver Creek Bridge |
| Lincoln Highway Marker (1) |
| Lincoln Highway Marker (2) |
| Lincoln Highway-Raccoon River Rural Segment |
| Lincoln Highway-West Beaver Creek Abandoned Segment |
| Lincoln Highway-West Greene County Rural Segment |
| Lincoln Hotel |
| Lincoln School |
| Lincoln School |
| Lincoln Statue |
| Lincoln Township Mausoleum |
| Linden Flats |
| Linden Heights Historic District |
| Lindsay, James E., House |
| Linograph Company Building, The |
| Linsay House |
| Lippincott, John, House |
| Lisbon Main Street Historic District |
| Lisbon Methodist Church |
| Littig Brothers/Mengel & Klindt/Eagle Brewery |
Data from United States Park Service and Wikidata
