California - Area of significance: Architecture
| Oroville Carnegie Library |
| Oroville Chinese Temple |
| Oroville Commercial District (old) |
| Oroville Inn |
| Ostrander Lake Ski Hut |
| Osuna, Juan Maria, Adobe |
| Our Lady of the Wayside |
| Outdoor Art Club |
| Outlands in the Eighty Acres |
| Outlet Gates and Gatekeeper's Cabin |
| Oviatt, James, Building |
| Oxnard, Henry T., Historic District |
| Oxnard Public Library |
| Pacheco, Don Fernando, Adobe |
| Pacific Coast Railway Company Grain Warehouse |
| Pacific Electric Etiwanda Depot |
| Pacific Electric Railroad Bridge |
| Pacific Electric Railway Company Substation No. 8 |
| Pacific Electric Sub-Station No. 14 |
| Pacific Gas and Electric Company General Office Building and Annex |
| Pacific Gas and Electric Company Substation J |
| Pacific Gas & Electric Company Building |
| Pacific Press Building |
| Packard Library |
| Paddison Ranch Buildings |
| Paige Motor Car Co. Building |
| Palace Hotel |
| Palace of Fine and Decorative Arts, Treasure Island |
| Palmer, Annie, House |
| Palmer, Judge Augustus C., House |
| Palmetto Court |
| Palm Springs Aerial Tramway Mountain Station |
| Palm Springs City Hall |
| Palm Springs Desert Museum |
| Palm Springs Municipal Airport Terminal |
| Palm Springs Tramway Valley Station |
| Palm Springs Unified School District Educational Administrative Center |
| Palo Alto Medical Clinic |
| Palo Alto Southern Pacific Railroad Depot |
| Palo Alto Stock Farm Horse Barn |
| Palomares, Ygnacio, Adobe |
| Palos Verdes Public Library and Art Gallery |
| Panama Hotel |
| Panoramic Hill |
| Pantages, Alexander, Theater |
| Paramount Theatre |
| Pardee House |
| Park Apartments |
| Parker House |
| Park Headquarters, Lassen Volcanic National Park |
| Parkhurst Building |
| Park Place-Arroyo Terrace Historic District |
| Park Place Methodist Episcopal Church South |
| Park Street Historic Commercial District |
| Park View Hotel |
| Parmelee, Lou Ellen, House |
| Parra, Miguel, Adobe |
| Parsons Memorial Lodge |
| Pasadena Avenue Historic District |
| Pasadena Civic Center District |
| Pasadena Playhouse |
| Pasadena Playhouse Historic District |
| Patio del Moro |
| Patrick Ranch House |
| Patterson Branch Library |
| Patterson, George Washington, Ranch-Ardenwood |
| Paugh, William J., House |
| Payne, Theodore F., House |
| PCF 816 (patrol craft fast) |
| Pear Lake Ski Hut |
| Pearlman Mountain Cabin |
| Pegfair Estates Historic District |
| Pegler, John Carlton, House |
| Pellissier Building |
| Peralta, Antonio Maria, House |
| Peralta House |
| Peralta, Luis Maria, Adobe |
| Pereira Octagon Barn |
| Perris Depot |
| Petaluma Adobe |
| Petaluma Historic Commercial District |
| Petaluma Silk Mill |
| Petaluma Woman’s Club |
| Peterson House |
| Peterson, Robert O.-Russell Forester House |
| Petitfils-Boos House |
| Pettigrew House |
| Pflueger, Timothy L., House |
| PG&E Powerhouse |
| Phelps, Abner, House |
| Phi Delta Theta Chapter House |
| Phillips House |
| Phillipshurst-Riverwood |
| Phillips Mansion |
| Philomathean Clubhouse |
| Physicians Building |
| Pico, Romulo, Adobe |
| Piedras Blancas Light Station |
| Pierce Ranch |
| Pier One |
Data from United States Park Service and Wikidata
