Maryland - Criteria: A (event)
| Sharp Street Memorial United Methodist Church and Community House |
| Sheffer, Daniel, Farm |
| Shoemaker, Henry, Farmhouse |
| Shrewsbury Church |
| SIGSBEE |
| SILVER HEEL (log canoe) |
| Silver Spring Baltimore and Ohio Railroad Station |
| Sion Hill |
| Slate Ridge School |
| Smeltzer, Henry, Farmstead |
| Smith, Harry, House |
| Snively Farm |
| Sonneborn Building |
| Sotterley |
| South Central Avenue Historic District |
| South Chesapeake City Historic District |
| Southern District Police Station |
| Southern Terminal, Susquehanna and Tidewater Canal |
| South Prospect Street Historic District |
| South River Club |
| Spacecraft Magnetic Test Facility |
| Sprechers Mill House |
| Springfield Presbyterian Church |
| Spring Hill Church |
| St. Alphonsus' Church, Rectory, Convent and Halle |
| Stancioff House |
| Standard Oil Building |
| St. Andrew's Church |
| Stanley Institute |
| STANLEY NORMAN |
| Stanton Center |
| Stanton's Mill |
| St. Bartholomew's Episcopal Church |
| St. Brigid's School and Convent |
| St. Charles College Historic District |
| St. Clement's Island Historic District |
| St. Elizabeth of Hungary |
| Stevensville Bank |
| Stevensville Historic District |
| Stewart's Department Store |
| St. Francis Xavier Church |
| St. Francis Xavier Church and Newtown Manor House |
| St. George's Parish Vestry House |
| Stieff Silver Company Factory |
| St. Ignatius Church |
| St. Ignatius Church |
| St. Ignatius Roman Catholic Church |
| Still Pond Historic District |
| St. James Church |
| St. John's Chapel of St. Michael's Parish |
| St. John's Church |
| St. John's Church |
| St. John's Methodist Episcopal Church and Joshua Thomas Chapel |
| St. John's Protestant Episcopal Church |
| St. Leo's Church |
| St. Luke's Church |
| St. Luke's Church |
| St. Mary's Benefical Society Hall |
| St. Mary's Church |
| St. Marys City Historic District |
| St. Mary's Seminary Chapel |
| St. Matthew's Church |
| St. Michael's Church |
| St. Michael's Church Complex |
| St. Michaels Historic District |
| Stone Hall |
| Stone Hill Historic District |
| Stoneleigh Historic District |
| St. Paul's Cemetery |
| St. Paul's Chapel |
| St. Paul's Church |
| St. Paul's Church Rectory |
| St. Paul's Episcopal Church |
| St. Paul's Parish Church |
| St. Peter's Church |
| St. Peter the Apostle Church and Buildings |
| St. Thomas Manor |
| St. Vincent De Paul Roman Catholic Church |
| Sudler's Conclusion |
| Sumner, Charles, Post #25, Grand Army of the Republic |
| Surratt House |
| SUSAN MAY |
| Swiss Steam Laundry Building |
| Sycamore Cottage |
| Sydenham Hospital for Communicable Diseases |
| Sykesville Historic District |
| Tammany |
| Taneytown Historic District |
| Taylor, David W., Model Basin |
| TENNISON, WM. B. (Chesapeake Bay Bugeye) |
| Terminal Warehouse |
| Thainston |
| Third Addition to Rockville and Old St. Mary's Church and Cemetery |
| Thomas and Company Cannery |
| Thomas Point Shoals Light Station |
| Thomas Run Church |
| Thomas Viaduct, Baltimore & Ohio Railroad |
| THOMAS W. CLYDE |
| Thornton |
| Tidewater Inn |
Data from United States Park Service and Wikidata
