Florida - Criteria: C (architecture/engineering)
| Neilson House |
| Nelmar Terrace Historic District |
| Nelson and Company Historic District |
| Newberry Historic District |
| Newell Hall |
| Newnansville Town Site |
| New River Inn |
| New Smyrna Beach Historic District |
| New Smyrna Sugar Mill Ruins |
| Nielsen, Lucienne, House |
| Nike Missile Site HM-69 |
| N.K. SYMI (Sponge Diving Boat) |
| Nokomis Beach Pavilion |
| Normandy Isles Historic District |
| North Avenue Historic District |
| Northboro Park Historic District |
| North City Historic District |
| Northeast Bartow Residential District |
| Northeast Gainesville Residential District |
| North Franklin Street Historic District |
| North Hill Preservation District |
| North Plant City Residential District |
| North Shore Historic District |
| North Shore Historic District |
| North Woodlawn Cemetery |
| Northwood, Old, Historic District |
| Norton, Gould Hyde, House |
| Norton, Robert Lee, House |
| Nyberg-Swanson House |
| Oak Hill Cemetery |
| Oakland Park Elementary School |
| Oates Building |
| Ocala Historic Commercial District |
| Ocala Historic District |
| Ocala Union Station |
| Ocean Spray Hotel |
| Ocoee Christian Church |
| Old Baker County Courthouse |
| Old Bradford County Courthouse |
| Old Calhoun County Courthouse |
| Old Christ Church |
| Old City Waterworks |
| Old Gainesville Depot |
| Old Hamilton County Jail |
| Old Holy Redeemer Catholic Church |
| Old Live Oak City Hall |
| Old Lucerne Historic Residential District |
| Old Orlando Railroad Depot |
| Old Ortega Historic District |
| Old Palm Beach Junior College Building |
| Old People's Home |
| Old Philadelphia Presbyterian Church |
| Old Post Office and Customshouse |
| Old School House |
| Olds Hall |
| Old Spanish Monastery |
| Old St. Johns County Jail |
| Old St. Luke's Hospital |
| Old Tampa Children's Home |
| Old US Post Office and Courthouse |
| Old Wakulla County Courthouse |
| O'Leno State Park |
| Ollinger-Cobb House |
| Olympia School |
| Olympia Theater and Office Building |
| Opa-locka Bank |
| Opa-Locka Company Administration Building |
| Opa-Locka Railroad Station |
| Operations and Checkout Building |
| Orange City Historic District |
| Orange City Town Hall |
| Orange Park Elementary School |
| Orange Park Negro Elementary School |
| O'Reilly House |
| Original Town of Fernandina Historic Site |
| Ormond Fire House |
| Ormond Hotel |
| Ormond Yacht Club |
| Osceola Apartment Hotel |
| Osceola County Courthouse |
| Osceola Park Historic Residential District |
| Osprey Archeological and Historic Site |
| Osprey School |
| Out of Door School |
| Overtown Historic District |
| Pahokee High School |
| Palace of Florence Apartments |
| Palafox Historic District |
| Palatka North Historic District |
| Palatka South Historic District |
| Palm Beach Daily News Building |
| Palm Beach Hotel |
| Palm Beach Mercantile Company |
| Palm Beach Town Hall |
| Palm Beach Winter Club |
| Palm Cottage |
| Palmer House |
| Palmerin Hotel |
| Palmer, John Denham, House |
| Palmer-Perkins House |
Data from United States Park Service and Wikidata
