Pennsylvania - Criteria: C (architecture/engineering)
| Poth, Frederick A., Houses, |
| Potter-Allison Farm |
| Potter County Courthouse |
| Pottsgrove Mansion |
| Pottstown Landing Historic District |
| Pottstown Roller Mill |
| Pottsville Armory |
| Pottsville Downtown Historic District |
| Powell Farm |
| Powell, John, House |
| Powelton Historic District |
| Powelton, The |
| Powers, Thomas, School |
| Presque Isle Light |
| Presser Home for Retired Music Teachers |
| Price, Joseph, House |
| Priestley, Dr. Joseph, House |
| Primitive Hall |
| Princeton Club |
| Promised Land State Park-Bear Wallow Cabins |
| Promised Land State Park Whittaker Lodge District |
| Prospect Junior High and Elementary School |
| Protection of the Flag Monument |
| Protestant Episcopal Church of the Saviour |
| Pusey, Caleb, House |
| Pusey-Crozier Mill Historic District |
| Pusey, Joshua, House |
| Quaker Bridge |
| Quaker Manor House |
| Quakertown Historic District |
| Quakertown Passenger and Freight Station |
| Quay, Rev. Anderson B., House |
| Queen Anne Historic District |
| Quiet Valley Farm |
| Rabb, Andrew, House |
| Racoon Creek RDA |
| Radnor Friends Meetinghouse |
| Rafsnyder-Welsh House |
| Railroad Borough Historic District |
| Ralston, Robert, School |
| Ramcat Historic District |
| Ramsey, J. Sylvester, School |
| Randolph House |
| Rapp's Bridge |
| Ravensburg State Park |
| Raymond, Charles and Joseph, Houses |
| Reading Company Grain Elevator |
| Reading Furnace Historic District |
| Reading-Halls Station Bridge |
| Reading Hardware Company |
| Reading Hardware Company Butt Works |
| Reading Railroad Freight Station |
| Reading Railroad Passenger Station-Tamaqua |
| Reading Railroad Station |
| Reading Terminal and Trainshed |
| Read, Thomas Buchanan, School |
| Real Estate Building |
| Rebersburg Historic District |
| Red Hill Church and School |
| Red Hill Historic District |
| Red Lion Borough Historic District |
| Red Men Hall |
| Red Run Covered Bridge |
| Red Run Lodge |
| Reed, Charles Manning, Mansion |
| Regent-Rennoc Court |
| Regester Log House |
| Reiff Farm |
| Reilly Brothers and Raub Building |
| Reinholds Station Trinity Chapel |
| Reppert-Gabler House |
| Revloc Historic District |
| Rex Covered Bridge |
| Rex House |
| Rex, John, Farm |
| Reyer, Peter and Catherine, Farmhouse |
| Reymer Brothers Candy Factory |
| Reynolds, Gen. John F., School |
| Reynolds-Morris House |
| Rhoads Homestead |
| Rhoads-Lorah House and Barn |
| Rice-Pennebecker Farm |
| Rice's Landing Historic District |
| Richardson, Joseph, House |
| Richmond School |
| Ricketts, Clemuel, Mansion |
| Ridge Avenue Bridge in Philadelphia |
| Ridge Avenue Farmers' Market |
| Ridge Road Bridge, Stewartstown Railroad |
| Ridge Valley Rural Historic District |
| Ridgewood Farm |
| Ridgway Armory |
| Ridgway Historic District |
| Riegel, Benjamin, House |
| Riegel Covered Bridge No. 6 |
| Rieser Mill |
| Rieser-Shoemaker Farm |
| Rieth, Andreas, Homestead |
| Ringgold Place |
| Ringland Tavern |
Data from United States Park Service and Wikidata
