Oregon - Area of significance: Architecture
| Oregon State Hospital Historic District |
| Oregon State Hospital Historic District |
| Oregon State Soldier's Home Hospital |
| Oregon State University Historic District |
| Oregon Trunk Passenger and Freight Station |
| Oregon-Washington Railroad & Navigation Company Passenger Station |
| Oriental Apartments |
| Ormonde Apartment Building |
| Orth, John, House |
| Osborn Hotel |
| Otis Elevator Company Building |
| Ott, David and Marianne, House |
| Our Lady of Perpetual Help Roman Catholic Church |
| Owyhee Grocery |
| Pacific Building |
| Pacific Coast Biscuit Company Building |
| Pacific Hardware and Steel Company Warehouse |
| Packard Service Building |
| Page and Son Apartments |
| Page, Judge C. H., House |
| Palace Hotel |
| Palestine Lodge |
| Pallay Apartments |
| Palmer House |
| Palmer, John, House |
| Paramount Theatre |
| Parelius, Martin, Fourplex |
| Parkdale Ranger Station |
| Parker, J. J. and Hazel, House |
| Parker Meadows Shelter |
| Parker, Moses, House |
| Parker School |
| Parkview Apartments |
| Parrish, William Albert and Anna May Bristow, Farmstead |
| Parrott, Moses, House |
| Parsons, John and Elsie, House |
| Parsons, Reginald, Dead Indian Lodge |
| Paterson, Thomas M. and Alla M., House |
| Patterson-Stratton House |
| Patton, Hamilton and Edith, House |
| Paulina Lake Guard Station |
| Paulson-Gregory House |
| Paulson, John E. and Christina, House |
| Paulus, Christopher, Building |
| Peacock Lane Historic District |
| Pearson Mortuary |
| Peck Bros. and Bartle Tire Service Company Building |
| Pedigrift, S. and Sarah J., House |
| Peery, E.C., Building |
| Pelota Fronton |
| Pelton, John and Charlotte, House |
| Pernot, Dr. Henry S., House |
| Perozzi, Domingo, House |
| Peters, A. V., House |
| Peterson, J.H., Machine Shop |
| Petzold, Richard B., Building |
| Petzold, Richard, House |
| Pfunder, Louis, House |
| Phillips, John, House |
| Philomath College |
| Pi Beta Phi Sorority House |
| Pickel, Dr. E. B., Rental House |
| Pierce, Edgar T., House |
| Piggott, Charles, House |
| Pioneer Courthouse |
| Pioneer Hall, Linfield College |
| Piper, Charles, Building |
| Pipes Family House |
| Pipes, George, House |
| Pipes, Martin Luther, House |
| Pittock Block |
| Pittock Mansion |
| Pleasant Grove Presbyterian Church |
| Point Comfort Lodge |
| Polhemus, James S., House |
| Polk County Bank |
| Poole, Otho, House |
| Port, Dr. Luke A., House |
| Porter-Brasfield House |
| Portland Art Museum |
| Portland City Hall |
| Portland Fire Station No. 17 |
| Portland Fire Station No. 23 |
| Portland Fire Station No. 7 |
| Portland Garden Club |
| Portland Golf Club Clubhouse and Golf Course |
| Portland New Chinatown-Japantown Historic District |
| Portland Police Block |
| Portland Public Service Building |
| Portland Skidmore/Old Town Historic District |
| PORTLAND (Steam Tug) |
| Portland Thirteenth Avenue Historic District |
| Portland Van and Storage Building |
| Portland Yamhill Historic District |
| Port-Manning House |
| Port Orford Coast Guard Station |
| Posey, John V. G., House |
| Postal Building |
| Postal Employees Credit Union |
| Post and King Saloon |
Data from United States Park Service and Wikidata
