Wisconsin - Criteria: C (architecture/engineering)
| Saint Ann's Catholic Church and Cemetery |
| Saint Bernard's Chruch Complex |
| Saint George Melkite Catholic Church |
| Saint James Court Apartments |
| Saint John Evangelical Lutheran Church |
| Saint Luke's Church Complex |
| Saint Peter's Evangelical Lutheran Church |
| Saints Peter and Paul Roman Catholic Church Complex |
| Saint Vincent's Infant Asylum |
| Salem Evangelical Church |
| Salem Evangelical Church |
| Salsbury Row House |
| Sauk City Fire Station |
| Sauk City High School |
| Sauk County Courthouse |
| Schendel, Reinhard and Amelia, House |
| Schofield, Robert, House |
| Schuetz, E.K., House |
| Schumann, Frederick, Farmstead |
| Schuster, George, House and Carriage Shed |
| Schuttler, Henry and Mary, House |
| Scott, T. B., Free Library |
| Second Church of Christ Scientist |
| Security Savings Bank |
| Senn, John L., House |
| Sensenbrenner, J. Leslie, House |
| Sevona Cabin |
| Sharrow, Frances Kurth, House |
| Shattuck, Franklyn C., House |
| Shawano Post Office |
| Sheboygan County Courthouse |
| Sheboygan Light, Power and Railway Company Car #26 |
| Sheboygan Theater |
| Sheeley House |
| Shekey, Albert and Mary, House |
| Sherman Avenue Historic District |
| Sherman House |
| Sherry, Henry, House |
| Sherwood Point Light Station |
| Shoop Building |
| Shopiere Congregational Church |
| Shorewood Historic District |
| Shot Tower |
| Siegner, George V., House |
| Silver Dome Ballroom, The |
| Simeon Mills Historic District |
| Simmons, Gilbert M., Memorial Library |
| Simmons Island Beach House |
| Sixth Church of Christ, Scientist |
| Skindrud, Eric and Jerome, Farm |
| Skumsrud, Nils, House |
| Smith, Adam and Mary, House |
| Smith, Camillia, House |
| Smith, Francis West, House |
| Smith, John, House |
| Smith, Lloyd R., House |
| Smith, Richard C., House |
| Smyth Road Bridge |
| Sniteman, Charles C. and Katharyn, House |
| Society Hill Historic District |
| Soo Line Depot |
| Soo Line High Bridge |
| Soo Line Locomotive 2719 |
| South Branch Library |
| South Dickason Boulevard Residential Historic District |
| South Main Street Historic District |
| South Main Street Historic District |
| South Main Street Historic District |
| South Milwaukee Passenger Station |
| South Milwaukee Post Office |
| Southport Beach House |
| Southside Historic District |
| South Washington Street Historic District |
| Southwest Side Historic District |
| Sparta Free Library |
| Sparta Masonic Temple |
| Spensley Farm |
| Spooner-Haight Farmstead |
| St. Andrew's Church |
| St. Andrews, Frank, House |
| Star Theatre |
| State Bank of Wisconsin |
| State Office Building |
| St. Augustine Catholic Church and Cemetery |
| St. Augustine Church |
| St Croix County Courthouse |
| Steam Locomotive #1385 |
| Stebbins, Edward N. and Mary T., House |
| Steckart and Falck Double Block |
| Steensland, Halle, House |
| Steiner, John, Store |
| Steinle Turret Machine Company |
| Steinman, John C. and Barbara, House |
| Steven House |
| Stewart, Hiram C., House |
| St. Germain dit Gauthier House |
| St. James Episcopal Church |
| St. John Chrysostom Church |
| St. John of God Roman Catholic Church, Convent, and School |
| St. John's Episcopal Church |
Data from United States Park Service and Wikidata
