Ohio - Role: Building
| Mount Oval |
| Mount Zion Baptist Church |
| Mount Zion Presbyterian Church |
| Mt. Healthy Public School |
| Mt. Tabor Church Building, Cemetery and Hitching Lot |
| Mueller Brewery |
| Mueller, Christ, House |
| Mueller Electric Company Building |
| Mumma, Jacob H. W., House |
| Municipal Building |
| Municipal Light Plant |
| Munson, Judge Albert, House |
| Murphy, Daniel, Log House |
| Murray Hill School |
| Murschel House |
| Muskingum County Courthouse And Jail |
| Musser, Henry, House |
| Mutual Home & Savings Association Building |
| Myer House |
| Myers Block-Home Company Building |
| Myers Daily Market |
| Myers Hall |
| Nafzger-Miller House |
| NASA Lewis Research Center-Development Engineering Building & Annex |
| Nathaniel Hawthorne Elementary School |
| National Home, Daughters of America |
| National Town and Country Club |
| Neal Clothing |
| Neal Terrace |
| Neely-Sieber House |
| Neff Apartments |
| Neff, Conrad, House |
| Neff, Edward E., House |
| Nelson, Luman, House |
| Neukom, Albert, House |
| Newark High School |
| New Baltimore Inn |
| Newberry Township School |
| Newcom House |
| New Concord-Union High School |
| New England Building |
| New England Lodge |
| New Garden Monthly Meetinghouse |
| New Hayden Building |
| New Lyme Institute |
| New Lyme Town Hall |
| Newman, William, House |
| New Market Township Community House |
| New Richmond Water Works and Electric Station |
| New Straitsville School |
| Newton Falls United Service Organization (USO) Center |
| Newton, Judge Eben, House |
| New York Central Freight House |
| Nichols, Eli, Farm |
| Nichols, John H., House |
| Nicholson, James, House |
| Nichols, Walter, House |
| Nickel, Old, Plate Railroad Depot |
| Niles Masonic Temple |
| Nimocks House |
| Ninchelser, Dr., House |
| No. 5 Fire Station |
| Noble County Jail and Sheriff's Office |
| Noble, Jonathan, House |
| Noble, Lewis, House |
| Nooney, William , House |
| Norfolk and Western Freight Station |
| Norfolk And Western Railroad Depot |
| Normandy Farms |
| North Baltimore Town Hall |
| North Bass School |
| Northern Ohio Blanket Mills |
| Northfield Town Hall |
| North High School |
| North Olmsted Town Hall |
| North Presbyterian Church |
| North Ridgeville City Hall |
| Northrop, Julia Carter, House |
| Northside United Methodist Church |
| North Ward District School |
| Norwalk Memorial Hospital |
| Norwalk Theatre |
| Norwell Residence |
| Norwood Municipal Building |
| Notre Dame Academy |
| Notre Dame Academy and Notre Dame High School |
| Notre Dame College of Ohio |
| Nurre-Royston House |
| Nutwood Place |
| Oak Hill |
| Oak Hill Cottage |
| Oak Hill Welsh Congregational Church |
| Oakland Cemetery Chapel and Superintendent's House and Office |
| Oakwood |
| Oakwood Cemetery Chapel |
| Oberlin Lake Shore And Michigan Southern Station |
| Octagon, The |
| Odd Fellows Hall |
| Odd Fellows Hall |
| Odd Fellows' Home for Orphans, Indigent and Aged |
Data from United States Park Service and Wikidata
