Massachusetts - Area of significance: Architecture
| Norfolk Street Historic District |
| Normal School Historic District |
| North Abington Depot |
| North Amherst Center Historic District |
| Northampton Downtown Historic District |
| Northampton State Hospital |
| Northampton Veterans Administration Hospital Historic District |
| North Andover Center Historic District |
| North Attleborough Town Center Historic District |
| North Avenue Congregational Church |
| North Avenue Rural Historic District |
| North Becket Village Historic District |
| North Bedford Historic District |
| Northbound and Southbound Stations |
| North Brookfield Town House |
| North Canal Historic District |
| North Christian Congregational Church |
| North Downtown Historic District |
| North Easton Historic District |
| North Easton Railroad Station |
| North Egremont Historic District |
| North Falmouth Village Historic District |
| Northfield Main Street Historic District |
| North Hadley Historic District |
| North Hatfield Historic District |
| North High Street Historic District |
| North Leverett Historic District |
| North Lexington Street Historic District |
| North Rochester Congregational Church |
| Northside Historic District |
| Northside Village Historic District |
| North Street Fire Station |
| North Taunton Baptist Church |
| North Terminal Garage |
| North Town Hall |
| North Uxbridge School |
| North Village Historic District |
| North Worcester Aid Society |
| Norton Center Historic District |
| Norton House |
| Norwell Village Area Historic District |
| Norwood-Hyatt House |
| Norwood Memorial Municipal Building |
| Notre Dame Catholic Church |
| Notre Dame School |
| Noves, Charles W., House |
| Nowland, J. Martin, House |
| Noyes, J.A., House |
| Noyes, James, House |
| Noyes-Parris House |
| Nye, Benjamin, Homestead |
| Nye, Elnathan, House |
| Oakdale Village Historic District |
| Oakes, Edward, House |
| Oakes, J. J., House |
| Oak Grove Cemetery |
| Oak Grove Farm |
| Oakham Center Historic District |
| Oak Knoll |
| Oak Square School |
| O'Brien, Richard, Three-Decker |
| O'Connor, James-John Trybowski Three-Decker |
| O'Connor, James, Three-Decker |
| Octagon House |
| Octagon House |
| Oddfellows Building |
| Odd Fellows Building |
| Odd Fellows Hall |
| Odd Fellows' Hall |
| Odd Fellows' Home |
| Ohabei Shalom Cemetery |
| O'Hara Waltham Dial Company |
| Olcott, John E., House |
| Old Barn |
| Old Billerica Road Historic District |
| Old Cambridge Baptist Church |
| Old Cambridge Historic District |
| Old Cambridgport Historic District |
| Old Castle |
| Old Central Fire Station |
| Old Central High School |
| Old Centre Historic District |
| Old Chapel |
| Old Chelmsford Garrison House Complex |
| Old Chestnut Hill Historic District |
| Old City Hall |
| Old Colony Iron Works-Nesmasket Mills Complex |
| Old Colony Railroad Station |
| Old Corner Bookstore |
| Old Curtisville Historic District |
| Old Douglas Center Historic District |
| Old Farm |
| Old Garrison House |
| Old Harbor U.S. Life Saving Station |
| Old Harvard Yard |
| Old Hose House |
| Old Indian Meeting House |
| Old Jail |
| Old King's Highway Historic District |
| Old Lynn High School |
Data from United States Park Service and Wikidata
