| Caballero, Fernán. Papers |
| Cafferty, Pastora San Juan. Papers |
| Calderino, Domizio, Commentaria in Martialem. Manuscript (Ms 11) |
| Camp Farr Collection |
| Campbell, Gladys. Papers |
| Campbell, Mrs. Patrick. Letters |
| Campbell, Wilbur and Valarie. Collection |
| Campbell, William Henry, Correspondence |
| Cannon, William B. Papers |
| Cappon, Alexander Patterson. Papers |
| Carl R. Moore. Papers |
| Carlson, Anton Julius. Papers |
| Carlson, LeRoy T. Papers |
| Carnegie Council On Children. Records |
| Carpenter, Frederick Ives. Papers |
| Carroll, Paul D. Papers |
| Carter, Henry Kendall. Papers |
| Carter, John Stewart. Papers |
| Castle, Henry Northrup. Papers |
| Castle, Mabel Wing. Papers |
| Cate, James Lea. Papers |
| Catterall, Helen Tunnicliff and Ralph C. H. Catterall Family. Papers |
| Central Pacific Railway Company. Blueprints |
| Century of Progress International Exposition Press Releases |
| Century of Progress International Exposition Publications |
| Century of Progress International Exposition Scrapbook |
| Chalmers, Charles H. The Helicopter |
| Chamberlin, Thomas Chrowder. Papers |
| Chambers, Caleb Stockton. Collection |
| Chandler, David. Collection |
| Chandrasekhar, Subrahmanyan. Papers |
| Chanute, Octave. Balloons in the Recent War |
| Chanute, Octave. Clippings on Aeronautics |
| Chanute, Octave. Collected Papers on Civil Engineering and Aeronautics |
| Chanute, Octave. Letters |
| Charles R. Walgreen Foundation. Records |
| Chaucer Research Project. Records |
| Checklist of the Official Publications of the Century of Progress International Exposition and Its Exhibitors |
| Chemins de fer du Centre, de Moulins a Roanne |
| Chessman, Dorothy Crowder. Papers |
| Chicago Belt Railroad Company. Records. |
| Chicago Child Welfare Exhibit. Collection |
| Chicago Citizens Commission to study the Disorders of Convention Week. Records |
| Chicago Citizens Police Committee. Records |
| Chicago Civil Service League. Records |
| Chicago Committee of Fifteen. Records |
| Chicago Committee to Save Lives in Chile Records |
| Chicago Commons. Collection |
| Chicago Drama Performances. Index |
| Chicago Fire Newspaper Collection |
| Chicago Foreign Language Press Survey. Records |
| Chicago Heart Association. Records |
| Chicago Institute, Academic and Pedagogic. Records |
| Chicago Laryngological and Ontological Society. Records |
| Chicago Library Club, Records |
| Chicago Manual Training School. Records |
| Chicago Mechanics' Institute. Records |
| Chicago Municipal Museum. Records |
| Chicago Neurological Society. Records |
| Chicago Pediatric Society. Records |
| Chicago Psychological Association. Records |
| Chicago Repertory Group Collection of Scripts and Scrapbooks |
| Chicago Review. Records |
| Chicago School of Civics and Philanthropy. Records |
| Chicago Society of Artists. Records |
| Chicago Zine Collection |
| Chirurgie aus Pierre Franco, Abstract of |
| Choice, Harriet. Collection |
| Church History Documents. Collection |
| Civic Disarmament Committee for Handgun Control. Records |
| Clark, Charles M. Record of Cases both Surgical and Medical, Operations, Post Mortem Examinations, etc. |
| Clark, E. Payson., Jr. Papers |
| Clark, Solomon H. Papers |
| Cleaner Air Committee of Hyde Park-Kenwood. Records |
| Clippings and Pamphlets on Galveston Harbor |
| Clippings on Social Evils in Chicago: Chiefly the Saloon |
| Clippings on Vice in Chicago |
| Clowes, Daniel. Archive |
| Coase, Ronald H. Papers |
| Coggeshalll, Lowell T., Papers |
| Cohen, Morris Raphael. Papers |
| Cohn, Bernard. Papers |
| Collection of Domestic and Medical Recipes |
| Collection of German Medical and Pharmaceutical Formulae |
| Collection of Medical Prescriptions and Notes on Folk Medicine |
| Collection of Recipes |
| Colonna, Asconia, Judicium in Caesarem Baronium de Monarchia Sicilia. Manuscript (Ms 13) |
| Colored Pathologic Drawings |
| Commentaries on Aristotle's Work |
| Commission on Freedom of the Press. Records |
| Commission on Race and Housing. Records |
| Committee for Aid to German and Austrian Scholars. Records |
| Committee on Science and Freedom. Records |
| Committee to Frame a World Constitution. Records |
| Compton, Arthur Holly. Papers |
| Cone, Fairfax M. Papers |
| Contract, Inscribed Tablet |
| Cook, Orator F. Papers |
| Cookbook |
| Correspondence, Estimates and Other Memoranda Relative to Motive Power on the Chicago & South Side Rapid Transit Company's Elevated Road |
| Coryell, Charles D. Papers |
| Coryn, W.J., Pain |
| Coulter, John Merle. Papers |
| Coulter, Merle C. Papers |
| Coulton, George Gordon. Papers |
| Council on Anthropology and Education. Records |
| Country Home for Convalescent Children. Board of Trustees. Records |
| Court Theatre. Records |
| Cowles, Henry C. Collection |
| Crane, Ronald S. Papers |
| Crawford, Wylie. Collection of Carilloniana |
| Cremation Association of America, Proceedings of the Convention |
| Crerar Library Collection of Patent Medicines |
| Crerar, Adams & Co. Collection |
| Crossroads International Student Center. Records |
| Cruikshank, George. Collection |
| Culbertson, William S., Papers |
| Culianu, Ioan P. Papers |
| Cullen, William. Practice of Physic |
| Cunningham, James Vincent. Papers |
| Cupani, Francisco. Hortus Catolicvs seu' illustrissimi et excellentissimi Principis Catholicae, ducis Misilmeres, comitis Uicaris, baronis Prizis |
| Cuppy, Will. Papers |
| Current Anthropology. Records |
| Currie, Brainerd. Papers |
| Curtiss, John Christlieb. Papers |