New York - Criteria: C (architecture/engineering)
| Niagara Falls City Hall |
| Niagara Falls Public Library |
| Niagara Falls School District Administration Building |
| Niagara Hudson Building, The |
| Niagara, The |
| Nichols High School |
| Nichols, William, Cobblestone Farmhouse |
| Niles Farmhouse |
| Nine Mile Creek Aqueduct |
| Nine Partners Meeting House and Cemetery |
| Niskayuna Railroad Station |
| Niskayuna Reformed Church |
| Nixon Homestead |
| No. 8 Thomas Street Building |
| Normandy Grange |
| Norman Vale |
| North, Benjamin D., House |
| North Blenheim Historic District |
| North Bloomfield School |
| North Broad Street Historic District |
| Northbrook Lodge |
| North Creek Railroad Station Complex |
| Northern River Street Historic District |
| North Grove Street Historic District |
| North Hempstead Town Hall |
| North Hillsdale Methodist Church |
| North Lyndon Schoolhouse |
| North Main and West Water Commercial Historic District |
| North Main-Bank Streets Historic District |
| North Main Street Historic District |
| North Main Street Historic District |
| North Main Street Historic District |
| North Main Street Historic District |
| North Main Street School |
| North Mansion and Tenant House |
| North Park Branch Library |
| Northport Public Library |
| North Presbyterian Church |
| North Ridge United Methodist Church |
| Northrup-Gilbert House |
| Northrup Hill School District 10 |
| North Salem Town Hall |
| North Salina Street Historic District |
| North Settlement Methodist Church |
| Northside Historic District |
| North Star School District No. 11 |
| North Street Friends Meetinghouse |
| Northville Historic District |
| Norton-Burnham House |
| Norton Village Historic District |
| Norway Baptist Church (former) |
| Norwich Pharmacal Company Warehouse |
| Norwood, Andrew S., House |
| Notleymere |
| Notman Bridge |
| Nott Memorial Hall |
| Nowak, Dr. John J., House |
| Nowland House |
| Noxon Bank Building |
| Noyes Cottage |
| Noyes, John, House |
| Nuits |
| Nut Grove |
| NYS Armory |
| Oakcliff |
| Oak Hill |
| Oak Hill Methodist Episcopal Church |
| Oak Hill Park Historic District |
| Oak Knitting Company |
| Oakley, John, House |
| Oak Street School |
| Oakwood Avenue Presbyterian Church |
| Oakwood Cemetery |
| Oakwood Cemetery |
| Oakwood Cemetery |
| Oaterhoudt Stone House |
| Oblong Friends Meetinghouse |
| O'Brien General Store and Post Office |
| Ocean Parkway Jewish Center |
| Ocean Parkway Station (Dual System BRT) |
| Octagonal Schoolhouse |
| Octagon, The |
| Odd Fellows Hall |
| Odd Fellows Lodge and Temple |
| Odell House |
| O'Donohue, C. A., House |
| Offerman Building |
| Office Building and U.S. Light-House Depot Complex |
| Office of the Register |
| Ogdensburg Armory |
| Ogdensburg Harbor Lighthouse |
| Ohave Shalom Synagogue |
| Oheka |
| Ohio Street Methodist Episcopal Church Complex |
| O'Kane Market and O'Kane Building |
| Old Allegany County Courthouse |
| Old Biology Hall |
| Old Blenheim Bridge |
| Old Brooklyn Fire Headquarters |
| Old Chappaqua Historic District |
Data from United States Park Service and Wikidata
