Ohio - Criteria: C (architecture/engineering)
| Sacred Heart of Jesus Rectory |
| Sail Loft |
| Saint Anne's Hill Historic District |
| Saint John the Evangelist Catholic Church Complex |
| Saint Joseph's Catholic Church |
| Saint Joseph's Roman Catholic Church |
| Saint Mary's Episcopal Church and Parish House |
| Saint Paul's Episcopal Church |
| Saint Philip's Episcopal Church |
| Salem Bear Creek Church, Salem Evangelical Lutheran Church |
| Salem Church |
| Salem Downtown Historic District |
| Salem Methodist Church Complex |
| Salem Methodist Episcopal Church |
| Salt Creek Covered Bridge |
| Salt House |
| Sanborn Hall |
| Sandiford, Robert, House |
| Sands, George F., School |
| Sandusky County Jail and Sheriff's House |
| Sandusky Street Historic District |
| Sarchet-Burgess House |
| Sarchet, Peter B., House |
| Satterthwaite, John, House |
| Saunders, Elizabeth Sheets, Farm |
| Savage-Stewart House |
| Sawyer-Curtis House |
| Sawyer, Louis, House |
| Saxony Apartment Building |
| """S"" Bridge II" |
| S Bridge, National Road |
| Scarlet Oaks |
| Schaller Memorial Building |
| Schantz, Adam Sr., House |
| Schine's Holland Theatre |
| Schine State Theatre |
| Schlee-Kemmler Building |
| Schmick, Charles Nelson, House |
| Schooley, Dr. Lindley, House and Office |
| Schriber, Hyman, Building |
| Schrock, Peter, Jr., Farm |
| Schueller, Erwin W., House |
| Schuffenecker, August Building |
| Schuter Carpenter Shop and House |
| Schweinfurth, Charles, House |
| Science Hill School |
| Scioto County Courthouse |
| Scioto Township District No. 2 Schoolhouse |
| Scofield-Sanor House |
| Scott, George, House |
| Scott, John, Barn and Granary |
| Scottown Covered Bridge |
| Scott, William, House |
| Scroggs House |
| Sears, A. B., House |
| Seborn, Frederick Augustus, House |
| Sebring, Frank, House |
| Second Baptist Church |
| Second Presbyterian Church |
| Second Presbyterian Church |
| Secor Hotel |
| Seeley, Uri, House |
| Seher, William, House |
| Seiberling, Charles Willard, House |
| Seip House |
| Selby Field |
| Selby, Orland, House |
| Selby Shoe Company Building |
| Selle Gear Company |
| Sells, Benjamin, House |
| Sells, Eliud, House |
| Seneca Hotel |
| Serquet, Emanuel and Frederick, Farm |
| Sessions House |
| Seville Jail |
| Seymour, William H., House |
| Shambaugh, George, House |
| Shandy Hall |
| Sharon Township Town Hall |
| Sharp, Morris, House |
| Sharp-Page House |
| Sharp, Samuel, House |
| Sharp, Stephen, House |
| Shaub, Martin, Mill Site/House |
| Shawen Acres |
| Shaw Farm |
| Shawnee Hotel |
| Shaw, Samuel, Residence |
| Shaw, Sylvester, Residence |
| Shedd-Dunn House |
| Sheffield Village Hall |
| Shelby House |
| Sheridan House |
| Sherman, John, Memorial Gateway |
| Sherwood-Davidson And Buckingham Houses |
| Shield's Block |
| Shield's, Edwin M., House |
| Shier, Carl H., House |
| Shiloh Baptist Church |
| Shinn Covered Bridge |
Data from United States Park Service and Wikidata
