Ohio - Significance region: Local
| J & M Trading Post |
| J & M Trading Post - Annex |
| John, Jehu, House |
| Johnson, Dustin, Residence |
| Johnson, E. J., House |
| Johnson-Humrickhouse House |
| Johnson, John, Farm |
| Johnson Steel Street Railway Company General Offices Building |
| Johnson, Thomas, House |
| Johnston-Crossland House |
| Johnston, William C., House And General Store |
| Johnstown Jail |
| Jones-Bowman House |
| Jones, Elam, Public House |
| Jones, Elijah Pelton, House |
| Jones Hall, Youngstown State University |
| Jones Home for Children |
| Jones Home Subdivisions Historic District |
| Jones, John J., House |
| Jones-Read-Touvelle House |
| Jones, W. H., Mansion |
| Joseph and Feiss Clothcraft Shops, The |
| Joyce, Jacob O., House |
| Judy Chapel |
| Julian and Kokenge Company |
| Julienne Girls Catholic High School |
| Jyurovat Farmstead |
| Kaiser, John, House |
| Karamu House |
| Karrer Barn |
| Karrer, Henry, House |
| Karshner Mound |
| Kauber, Warren F., Funeral Home |
| Kearns, George and Edward, Houses |
| Keeler, Diadatus, House |
| Kelley, Barney, House |
| Kelley, William, Hardware Store-Hayesville Odd Fellows Hall |
| Kellog, Ethol, House |
| Kellogg House |
| Kellogg, John, House and Barn |
| Kelly Family Home |
| Kemp, Lewis, House |
| Kendall, Virginia, State Park Historic District |
| Kendel Building |
| Kenilworth Avenue Historic District |
| Kenmore Boulevard Historic District |
| Kennedy Apartments and Commercial Block |
| Kennel, John, Jr., Farm |
| Kennel, John Sr., Farm |
| Kent, Charles House |
| Kent Jail |
| Kent, J., Residence |
| Kenton Courthouse Square Historic District |
| Kenton Public Library |
| Kent, Zeno, House |
| Kerber's Marine Grocery |
| Kern, Rufus A., House |
| Kerper and Melbourne Terrace Apartments |
| Kerr, Benjamin F., House |
| Kestler Building |
| Keyt, Gideon, House |
| Kies, Lewis, House |
| Kilbourn Commercial Building |
| Kilbourn, William, House |
| Kilgore Union Presbyterian Church |
| Kilpi Hall |
| Kimball, Addison, House |
| Kimball, Lemuel II, House |
| Kimball, Solomon, House |
| Kindleberger, Frederick, Stone House and Barn |
| Kindra, W. H., Apartments |
| King, Dr., House |
| King, George W., Mansion-Etowah |
| King-Phillips-Deibel House |
| King, William, House |
| Kinney, Aaron, House |
| Kinney, Eli, House |
| Kinney, James, Farmstead |
| Kinsey, The |
| Kinzer Mound |
| Kirby, Josiah, House |
| Kirby Road School |
| Kirkwood, Joseph, House |
| Kiser Mansion |
| Kishman Fish Company Buildings |
| Kittinger, David, Residence |
| Klaus Block |
| Knapp, William, House |
| Knights of Columbus Building |
| Knights of Pythias Hall |
| Knowlton, Dr. William A., House |
| Knox County Infirmary |
| Koch, John E., Jr., House |
| Koehne-Poast Farm |
| Kossuth Colony Historic District |
| Krause Building-Otto Moser's Cafe |
| Krause, John, House |
| Krippendorf Estate |
| Kroger Barnes Graf, Gretchen, House |
| Krug House |
Data from United States Park Service and Wikidata
