Pennsylvania - Area of significance: Architecture
| Smedley, Franklin, School |
| Smith Family Farmstead |
| Smith, Henry, Farm |
| Smith, Walter George, School |
| Smith, William, House |
| Smock Historic District |
| Smyser and English Pharmacy |
| Snellenburg's Clothing Factory |
| Snooks Covered Bridge |
| Snyder, Caspar, House |
| Snyder, Gov. Simon, Mansion |
| Snyder Mill |
| Snyder, William Penn, House |
| Social Service Building |
| Society Hill Historic District |
| Sodom Schoolhouse |
| Soldiers and Sailors Memorial Hall |
| Solitude Farm |
| Solomon House |
| Somerset County Courthouse |
| Sotcher Farmhouse |
| Souderton Historic District |
| Southampton Baptist Church and Cemetery |
| South Bethlehem Downtown Historic District |
| South Brook Farm |
| South Fork Fishing and Hunting Club Historic District |
| South Front Street Historic District |
| South, George W., Memorial Protestant Episcopal Church of the Advocate |
| South Side High School |
| South Side Market Building |
| South Tenth Street Bridge |
| South Ward School |
| Southwark District |
| Southwark Municipal Piers |
| Southwark School |
| South Wayne Historic District |
| Spalding Memorial Library-Tioga Point Museum |
| Spannuth Mill |
| Special Troops Armory |
| Speedwell Forge Mansion |
| Sperling Building |
| Spicker, Peter, House |
| Spinner House |
| Sprenger Brewery |
| Springdale Farm |
| Springdale Historic District |
| Springdale Historic District |
| Springer Farm |
| Springfield Public School |
| Spring Garden District |
| Spring Garden School No. 1 |
| Spring Garden School No. 2 |
| Spring Grove Borough Historic District |
| Spring Grove Farm and Distillery |
| Spring Grove Forge Mansion |
| Spring Mill Complex |
| Springton Manor Farm |
| Springtown Historic District |
| Spring Valley Historic District |
| Spruce Creek Rod and Gun Club |
| Square Tavern |
| Stanley |
| Stanley Theater and Clark Building |
| St. Anthony de Padua Parish School |
| St. Anthony Hall House |
| Stanton, Edwin M., School |
| Star Barn Complex |
| Star Junction Historic District |
| Starlight Station, New York, Ontario, and Western Railway |
| State Capitol Building, Pennsylvania |
| State Theatre |
| Stauffer, Christian, House |
| Stauffer, Dr. B., House |
| St. Augustine's Catholic Church |
| St. Boniface Roman Catholic Church |
| St. Clement's Protestant Episcopal Church |
| St. David's Church and Graveyard |
| Steckel, Daniel, House |
| Steelton High School |
| Stegmaier Brewery |
| Steinman Hardware Store |
| Stein Mill |
| St. Elisabeth’s Episcopal Church |
| St. Elizabeth's Convent |
| Stenton |
| Stephenson-Campbell House |
| Sterrett Sub-District School |
| Stevens High School |
| Stevens School |
| Stewart, Gen. Thomas J., Memorial Armory |
| Stewart, John, Houses |
| Stewartstown Engine House, Stewartstown Railroad |
| Stewartstown Railroad Station |
| Stewart, Walter and Gertrude May, Farmstead |
| St. Gabriel's Catholic Parish Complex |
| St. Gabriel's Episcopal Church, Old |
| St. Gabriel’s Roman Catholic Church Complex |
| St. George's Methodist Church |
| St. Gertrude Roman Catholic Church |
| Stirling |
Data from United States Park Service and Wikidata
