Ohio - Area of significance: Architecture
| Miner's Supply Store |
| Minster Elementary School |
| Mitchell, Charles, House |
| Mitchell Historic District |
| Mitchell, Randolph, House |
| Mitchell, Richard H., House |
| Mohawk Place Historic District |
| Mohrman-Jack-Evans House |
| Mo-John, Betsy, Cabin |
| Monitor House |
| Monmouth Building |
| Monnett Memorial M. E. Chapel |
| Monroe Bank |
| Monroe County Courthouse |
| Monroe School |
| Monroe Street Commercial Buildings |
| Monroe Theatre |
| Monroe Township Hall-Opera House |
| Montana Apartments |
| Monteith Hall |
| Montgomery County Courthouse |
| Montgomery Saltbox Houses |
| Mooney, William C., House |
| Moore, Charles H., House |
| Moore, Edward W. and Louise C., Estate |
| Moormann, Bernard H., House |
| Morehouse-Downes House |
| Moreland Theater Building |
| Morgan-Hueston House |
| Morgan Mansion |
| Morley, Lewis, House |
| Morris, C. E., 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 |
| Most Pure Heart Of Mary Church |
| Mother of Sorrows Church |
| Mother Thompson House |
| Mott Drug Store |
| Mound House |
| Mount Adams Public School |
| Mountain House |
| Mount Airy Forest |
| Mount Auburn Historic District |
| Mount Auburn School |
| Mount Liberty Tavern |
| Mount Oval |
| Mount Pleasant Historic District |
| Mount Sterling Historic District |
| Mount Union College District |
| Mount Victory Historic District |
| Mount Zion Presbyterian Church |
| Mt. Healthy Public School |
| Mt. Tabor Church Building, Cemetery and Hitching Lot |
| Mueller Brewery |
| Mueller, Christ, House |
| Muller, Daniel C., Carousel |
| Mumma, Jacob H. W., House |
| Municipal Building |
| Murphy, Daniel, Log House |
| Murray Hill School |
| Muskingum College Campus Historic District |
| Muskingum County Courthouse And Jail |
| Muskingum River Lock No. 10 And Canal |
| Musser, Henry, House |
| Mutual Home & Savings Association Building |
| Myer House |
| Myers Block-Home Company Building |
| Myers Daily Market |
| Myers Hall |
| Myrtle-Highview Historic District |
| Nathaniel Hawthorne Elementary School |
| National Home, Daughters of America |
| National Orphans' Home, Junior Order United American Mechanics |
| National Town and Country Club |
| Neal Clothing |
| Near Northside Historic District |
| Neely-Sieber House |
| Neff Apartments |
| Neff, Conrad, House |
| Neff, Edward E., House |
| Nela Park |
| Nelson, Luman, House |
| Nelsonville Historic District |
| Neukom, Albert, House |
| Newark Downtown Historic District |
| Newark High School |
| New Baltimore Inn |
| Newberry Township School |
| Newcom House |
| New England Building |
| New Garden Monthly Meetinghouse |
| New Hayden Building |
| New Indianola Historic District |
| New Lyme Town Hall |
Data from United States Park Service and Wikidata
