Ohio - Significance region: Local
| Melville-Milne, William Gordon, House |
| Memorial Hall |
| Mendon Town Hall |
| Mentor Village Hall |
| Mentor Village School |
| Mentzer-Sorrick Farm |
| Mercantile Library Building |
| Mercer Log House |
| Merrill, Edwin H., House |
| Merriman, Wells E., House |
| Merryman, Dr. James, House |
| Mertz, John, House |
| Merwin, George, House |
| Metcalf, Rev. Harlan, House |
| Methodist Church, Old |
| Methodist Church Parsonage |
| Methodist Episcopal Church |
| Methodist Episcopal Church |
| Methodist Episcopal Church of Painesville, The |
| Methodist Parsonage, Old |
| Metropolitan Block |
| Meyer House |
| Meyers, Capt., House |
| Miami-Erie Canal Lock No. 70 |
| Miami Monthly Meeting Historic District |
| Miami Street Grade School |
| Miami Valley Golf Course and Clubhouse |
| Michaels Farm |
| Middle Bass Club Historic District |
| Middleport Public Library |
| Middle Sandy Presbyterian Church |
| Midtown Historic District |
| Miles, Enos, House |
| Miles Park Historic District |
| Mill & Dunn Historic District |
| Millen-Schmidt House |
| Miller-Bissell Farmstead |
| Miller Block |
| Miller, Daniel, House |
| Miller, Daniel, House |
| Miller Farm |
| Miller, Frederick A., House-Broad Gables |
| Miller, Harvey, Residence |
| Miller, J.F., House |
| Miller, John, House |
| Miller-Knight House |
| Miller-Leuser Log House |
| Miller, Lewis, House |
| Miller, Peter, House |
| Millersburg Historic District |
| Miller, Thomas, House |
| Mill Hollow House, The |
| Milligan, Cuthbert, House |
| Mill Office and Post Office |
| Mills' Row |
| Mill Worker House No. 1 |
| Mill Worker House No. 3 |
| Mill Worker House No. 4 |
| Mill Worker House No. 5 |
| Minch, Capt., House |
| Mitchell, Charles, House |
| Mitchell, Randolph, House |
| Moar Mound And Village |
| Mohawk Place Historic District |
| Monmouth Building |
| Monnett Memorial M. E. Chapel |
| Monroe Bank |
| Monroe School |
| Monroe Street Commercial Buildings |
| Monroe Theatre |
| Monroe Township Hall-Opera House |
| Montana Apartments |
| Monteith Hall |
| Montgomery Saltbox Houses |
| Mooney, William C., House |
| Moonville Tunnel |
| Moore, Charles H., House |
| Moore, Leonard M., House |
| Moore, Philip, Stone House |
| Moormann, Bernard H., House |
| Morehouse-Downes House |
| Moreland Theater Building |
| Morgan, Garrett, House |
| Morgan-Hueston House |
| Morgan Mansion |
| Morgan Township House |
| Morris House |
| Morrison House |
| Morristown Historic District |
| Morrow County Courthouse And Jail |
| Morrow-Overman-Fairley House |
| Morvilius Opera House |
| Mosgrove, Dr. Adam, House |
| Mosher House |
| Moss-Foster House |
| Most Pure Heart Of Mary Church |
| Mother of Sorrows Church |
| Mott Drug Store |
| Mound Cemetery Mound |
| Mound House |
Data from United States Park Service and Wikidata
