| Sage, Evan Taylor. Manuscripts |
| Sahlins, Marshall. Papers |
| Salgado Correa, Alejo, Libro nombrado memorial de martires de Hespana. Manuscript (Ms 64) |
| Salisbury, Rollin D. Papers |
| Salloch, William and Marianne, Collection of Prints and Drawings: “People with Books.” |
| Sand, Knud Aage Buchtrup. Legal Medicine, its Origin, Development and Status in Modern Times, with Special Regard to Denmark |
| Sandburg, Carl and Ruth Falkenau. Correspondence |
| Sandburg, Carl-Joseph Halle Schaffner. Collection |
| Sanders, Edgar. Papers |
| Sanders, Edgar. Scrapbooks |
| Sarton, May. Collection |
| Saxe, John Godfrey. Collection |
| Say, Jean Baptiste. Collection |
| Scammon, Jonathon Young. Papers |
| Schaffner, Joseph Halle, Collection in the History of Science |
| Schein, Marcel. Papers |
| Schevill, Ferdinand. Papers |
| Schilling, George A., Papers |
| Schmitt, Bernadotte E. Papers |
| Schneider, David M. Papers |
| Schomerus, C.P. Ueber die durch das gleichzeitige Vorhandensein eines Herzleidens, einer Struma und eines Exophthalmus characterisirte Krankheit |
| Schramm, David N. Papers |
| Schultz, Arthur W. Papers |
| Schulz, Marjorie Preston. Papers |
| Schwab, Joseph J. Papers |
| Schwartz, Samuel. Papers |
| Schütze, Eva Watson. Photographs |
| Schütze, Martin. Papers |
| Scotch, Hank. Moby Dick Comic Books. Collection |
| Scott, Arthur Pearson. Papers |
| Scott, Hugh M. Papers |
| Scranton, Robert L. Papers |
| Scrapbook |
| Scrapbook of Clippings on the Boston Subway |
| Scrapbook of the Chicago Subway System |
| Scrapbook on Gas Use |
| Sebastian of Naples, Declarationes supplectiones as remissiones. Manuscript (Ms 41) |
| Seneca, Lucius Annaeus, Spurious works. Manuscript (Ms 42) |
| Senn, Nicholas Papers |
| Seven Woods Press. Records |
| Shackelford, Benjamin. Papers |
| Shapey, Ralph. Papers |
| Sharp, Benjamin. Peary's North Greenland Expedition and the Relief |
| Shaw, Albert E. Papers |
| Sheean, Vincent and Ruth Falkenau. Correspondence |
| Sheet Music. Collection |
| Shepherd, David. Papers |
| Sherer, Albert. Papers |
| Sherwood, Andrew and Clark. Collection |
| Shillinglaw, David Lee. Papers |
| Shimer, Henry. Epidemic Diseases |
| Shorey, Paul. Papers |
| Shortall, Harrington. Papers |
| Silbert, Layle. Papers |
| Silverberg, James. Papers |
| Simon, Bernece K. Papers |
| Simons, Henry C. Papers |
| Simons, Hi. Papers |
| Simpson, John A. Papers |
| Simpson, John A.. Papers. Addenda |
| Simpson, Tracy W. Electrification Project : The Illinois Central Railroad Company Suburban Service at Chicago, Ill. |
| Simson, Otto G. von. Papers |
| Singer, Milton. Papers |
| Sir Nicholas Bacon Collection of English Court and Manorial Documents |
| Sketch of East High Green Lead Mine |
| Slavery and Indentured Servitude Collection |
| Slotin, Louis Memorial Fund. Records |
| Slotkin, Elizabeth J. Papers |
| Slotkin, James Sydney. Papers |
| Slye, Maud. Papers |
| Small, Albion W.. Papers |
| Smith, Adolphe. Chicago and the Slaughter House Question : Inspection an Insufficient Guarantee |
| Smith, Goldwin. Collection |
| Smith, J. M. Powis. Papers |
| Smith, Joseph V. Papers |
| Smith, Maurine. Papers |
| Smith, Raymond T. Papers |
| Smith, Thomas Vernor. Papers |
| Smyth Family. Papers |
| Society of Medical History of Chicago, Bulletin and Correspondence |
| Society of Medical History of Chicago. Records |
| Soemmerring, Samuel Thomas von. Icones oculi humani |
| Solon, Israel. Collection |
| Sondheim, Harry B. and Branka J. Jewish Heritage Collection |
| Song Plugger Cards. Collection |
| Song Sheet and Broadside Poem. Collection |
| Sonnenschein, Robert. Collection |
| South Park Improvement Association. Records |
| South Side Academy. Records |
| Spallanzani, Lazzaro. Correspondence |
| Specielle Pathologie und Therapie |
| Spencer, William M. Collection of French Manuscripts |
| Spergel, Irving A. Papers |
| Sperring, Beverly A., Papers |
| Spike, Robert W. Papers |
| Spink, George. Collection |
| Squibb, Francis P. Papers |
| Stagg, Amos Alonzo. Papers |
| Stanfield, Reuel. Autobiography |
| Stanger, Philip. Collection |
| Stark, Johann Christian. Hebammen-Buch |
| Stark, Johann Christian. Über Frauenkrankheiten und Kinderkrankheiten |
| Starr, Frederick. Liberian Research Collection |
| Starr, Frederick. Mexican Manuscripts. Collection |
| Starr, Frederick. Papers |
| Statius, P. Papinius, Achilleid. Manuscript (Ms 704) |
| Steed, Gitel P. Papers |
| Steinbrecher, Frederick "Fritz". Collection |
| Steiner, John. Collection |
| Stenn, Frederick. Papers |
| Stent, G.C., Chinese Eunuchs: Or, the Origin, Character, Dress, Duties, and Preparation of the Castrati of China |
| Stephens, Alexander H. Collection |
| Stephenson, William A. F., Papers |
| Stevens, David H. Papers |
| Stevens, Warder W., Fruit Culture in Indiana |
| Stewart, Donald E. Papers |
| Stieglitz-Mathieu. Correspondence |
| Stiernberg, Ed. Collection |
| Stirn, Ernest W. and Henry J. Papers |
| Stoddard, William Osborn. Collection |
| Stone, Ursula Batchelder. Collection |
| Strauss, Herbert R. Collection of Theodore Roosevelt Papers |
| Strauss, Leo. Papers |
| Strong, Reuben Myron. History of the Stritch Medical School of Loyola University |
| Stroud, Drew McCord (Ryu Makoto). Papers |
| Stutz, John G. Papers |
| Sussman, Alan. Collection |
| Sutherland, Zena Bailey. Papers |
| Sweet, William Warren. Papers |
| Swerdlow, Noel M. Collection |
| Swift, Charles H. Papers |
| Swift, Harold. Papers |