Ohio - Role: Building
| Linaweaver, Dr. Albert, House |
| Lincoln Theatre |
| Lind Arcade |
| Linden Community and Recreation Center |
| Lindner Building |
| Lindsey Building |
| Linneman Building |
| Lion Knitting Mills |
| Liquid Carbonic Corporation Dry Ice Plant |
| Livingston, Alexander W., House |
| Lloyd, John Uri, House |
| Lock Tender's House and Inn |
| Lockwood, J. C., House |
| Loew-Define Grocery Store and Home |
| Loew's Theatre |
| Logan City Hall |
| Logan County Courthouse |
| Lombardy Apartment Building |
| Long and Third Commercial Building |
| Longenecker, Doctor, Office Building |
| Long-Mueller House |
| Long-Romspert House |
| Longwood Manor |
| Look About Lodge |
| Looker, Othniel, House |
| Lorain Carnegie Public Library |
| Lorain County Courthouse |
| Lorain Fire Station No. 1 |
| Lorain Lighthouse |
| Lorain YMCA Building |
| Lord, Addison, House |
| Lost Lane Farm |
| Lotz, Henry, Stone |
| Lovejoy, Carrie, House |
| Loveridge, Richard and Ann, House |
| Lowellville Railroad Station |
| Lowler's Tavern |
| Lowrie, S. Gale and Agnes P., House |
| Lubal Manufacturing and Distributing Company, The |
| Lucas County Courthouse and Jail |
| Lucas County Hospital and Nurse's Home |
| Luelleman, William, House |
| Luethstrom-Hurin House |
| Lundy, Benjamin, House |
| LuNeack House |
| Lunkenheimer, Frederick, House |
| Lutz-Martin Farm |
| Lutz's Tavern |
| Lyle, Samuel, Log House |
| Lyman, William, House |
| Lynnwood Farm |
| MacDonell House |
| Macedonia Church |
| Mace, Henry, House |
| Macksville Tavern |
| Macomb, Mary Worthington, House |
| Madam Fredin's Eden Park School and Neighboring Row House |
| Madeira Railroad Depot |
| Madison County Courthouse |
| Madison Seminary And Home |
| Mad River Block |
| Magruder Building |
| Mahoning County Courthouse |
| Mahoning National Bank Building |
| Main and Third Street Cluster |
| Main Building School |
| Main Street Buildings |
| Main Theatre |
| Malio House |
| Mallory, Ogden, House |
| Maltby, Henry, House |
| Manasseh Cutler Hall, Ohio University |
| Manse Hotel and Manse Hotel Annex |
| Mansfield, Judge, House |
| Mansfield Savings Bank |
| Mansfield Woman's Club |
| Mantua Center School |
| Maple-Dell |
| Maplewood |
| Maplewood Sanitorium |
| March, George, House |
| March, George, House |
| Mardot Antique Shop |
| Maria Stein Catholic Church and Rectory |
| Maria Stein Convent |
| Marion Catholic School |
| Marion County Courthouse |
| Marion County Telephone Company Building |
| Marion Township School District No. 3 |
| Marion Township Sub-District #8 School |
| Marion Women's Club Home |
| Market-Mohawk Center |
| Marks-Family House |
| Marlow Theatre |
| Marmon, Martin, House |
| Marquart-Mercer Farm |
| Marshall, David, House |
| Marshall, James E., House |
| Marsh, George H., Homestead and the Marsh Foundation School |
| Marsh, Joseph, House |
Data from United States Park Service and Wikidata
