Pennsylvania - Area of significance: Architecture
| National Bank of North Philadelphia |
| National Transit Building |
| Nazareth Hall Tract |
| Nazareth Historic District |
| Nearpass House |
| Nebinger, George W., School |
| Neff, Maj. John, Homestead |
| Neff Round Barn |
| Neill-Mauran House |
| Nelson, John H., House |
| Nesbit-Walker Farm |
| Nesquehoning High School |
| Neuweiler Brewery |
| New Berlin Presbyterian Church |
| New Castle Armory |
| New Century Clubhouse |
| New Colonial Hotel |
| New Era Building |
| New Freedom Railroad Station, Northern Central Railway |
| New Geneva Historic District |
| New Hope Village District |
| New Kensington Downtown Historic District |
| New Kensington Production Works Historic District |
| Newlin Mill Complex |
| Newlin Miller's House |
| Newlin, Nicholas, House |
| Newmyer, Peter and Jonathan, Farm |
| Newport Historic District |
| New Ringgold Gristmill |
| Newtown Friends Meetinghouse and Cemetery |
| Newtown Historic District |
| Newtown Presbyterian Church |
| Newville Historic District |
| New York Mutual Life Insurance Company Building |
| Nicholas, Jacob, House |
| Nichols, Jeremiah, School |
| Nineteenth Street Theater |
| Nissly-Stauffer Tobacco Warehouses |
| Nissly Swiss Chocolate Company |
| Nitre Hall |
| Noble, J. L. School |
| Nook, The |
| Noon, Philip, House |
| Normandy Farmstead |
| North Broad Street Mansion District |
| North Broad Street Station, Reading Company |
| North Charlotte Street Historic District |
| North East Historic District |
| Northeast Lancaster Township Historic District |
| Northeast Manual Training School |
| Northern Liberties Historic District |
| Northern National Bank |
| Northern Saving Fund and Safe Deposit Company |
| North Hill Historic District |
| North Prince Street Historic District |
| North Scranton Junior High School |
| Northumberland County Courthouse |
| Northumberland Historic District |
| North Warwick Historic and Archeological District |
| North Wayne Historic District |
| Northwest York Historic District |
| N. Shippen-Tobacco Avenue Historic District |
| N. Snellenburg Company Department Store Warehouse |
| Nugent Home for Baptists |
| Nutt, Adam Clarke, Mansion |
| Nutting Hall |
| Nyce Farm |
| Oakdale |
| Oakdale Public School |
| Oak Hall Historic District |
| Oak Hill Estate |
| Oakland Public School |
| Oaklands |
| Oak Park Historic District |
| Oaks Cloister |
| O'Connor, J.S., American Rich Cut Glassware Factory |
| Octagon Stone Schoolhouse |
| O'Donel House and Farm |
| Ogden House |
| Ogontz Hall |
| Ohringer Building |
| Oil City Armory |
| Oil City Downtown Commercial Historic District |
| Oil City North Side Historic District |
| Oil City South Side Historic District |
| Okehocking Historic District |
| Old Allegheny Rows Historic District |
| Old Brown's Mill School |
| Old City Hall |
| Old City Historic District |
| Old Conemaugh Borough Historic District |
| Old Customshouse |
| Old Downtown Harrisburg Commercial Historic District |
| Old Dry Road |
| Old Federal Reserve Bank |
| Old Germantown Academy And Headmasters' Houses |
| Old Heidelberg Apartments |
| Old Homestead |
| Old Hoopes School |
| Old Indiana County Courthouse |
Data from United States Park Service and Wikidata
