| Chester Cable Papers | 1965-1983, bulk 1971-1983 | | UP001162 |
| William Cahn Papers | circa 1940-1979 | | LP000808 |
| Arthur W. Calhoun Papers | 1899-1975 | | LP000503 |
| Mellie and Herbert S. Calvert Papers | circa 1920-1929 | | LP000778 |
| Clarice T. Campbell Papers | 1962-1979 | | UP000919 |
| Elise Hatt Campbell Papers | 1919-1943, bulk 1923-1939 | | UP001410 |
| Tom and Janet Canterbury Papers | 1963-1966 | | UP000635 |
| Lester Cappon Papers | 1888-1935 | | LP000804 |
| James B. Carey Papers | 1936-1973 | | LP001474 |
| Robert E. Carlson Papers | 1941-1942 | | LP001285 |
| Lawrence Carlstrom Papers | 1937 | | LP000175 |
| Dr. Louis B. Carrick Papers | 1938–1983 | | LP000061 |
| Louis B. Carrick Papers | 1912-1935 | | LP000061 |
| Monroe S. Causley, Jr. Papers | 1937–1943 | | LP001195 |
| Jerome P. Cavanagh Papers | 1960-1979 | | UP000379 |
| Elaine Rogan and Tor Cedervall Papers | circa 1933-1936 | | LP000200 |
| Center for Community Change Records | 1960-1979 | | UR000966 |
| W. Ellison Chalmers Papers | 1925-1938 | | LP000166 |
| Gordon W. Chapman Papers | 1934-1967 | | LP000923 |
| Cherboneau Place Cooperative Records | 1959-1986 | | UR001296 |
| Charles Chiakulas Papers | 1944-1968 | | LP000295 |
| Chicago Union Printers Baseball Association Records | 1970-1984 | | LR001527 |
| Children's Hospital of Michigan: Director of Laboratories Records | 1940-1980 | | UR001146 |
| Children’s Hospital of Michigan Records | 1886-1989 | | UR001244 |
| Ely Chinoy Papers | 1936-1983 | | LP001630 |
| Joseph Chrapkiewicz Papers | 1946-1962 | | LP000607 |
| Edith L. Christenson Papers | 1909-1974 | | LP000588 |
| Louis Ciccone Papers | 1945-1961 | | LP000137 |
| Cigar Makers Union No. 130 Records | 3 folders | | LR000067 |
| CIO Department of Education and Research Records | 1945-1968 | | LR000270 |
| CIO Executive Board Minutes and Proceedings | 1935-1955 | | LR000751_pub |
| CIO Housing Committee: Leo Goodman Records | 1940-1956 | | LR000689 |
| CIO Office of the Secretary-Treasurer Records | 1935-1960 | | LR000185 |
| CIO Political Action Committee (PAC) Records | circa 1943-1969 | | LR000647 |
| CIO Washington Office Records | 1950-1956 | | LR000548 |
| Citizen Action Records | 1979-1993, bulk 1980s | | UR001636 |
| Citizen's Crusade Against Poverty Records | 1964-1970, bulk 1965-1968 | | UR000516 |
| Citizens for a United Detroit Records | 1964 | | UR000484 |
| Citizens for Michigan Records | 1959-1962 | | UR000303 |
| Civil Rights Congress of Michigan Records | 1933-1963, bulk 1935-1955 | | UR000304 |
| Father Raymond S. Clancy Papers | 1931-1970 | | LP000499 |
| Charles J. Clark Papers | 1963-1976 | | LP000770 |
| Coalition of Labor Union Women Records | 1972-2001, bulk 1974-2001 | | LR000664 |
| Coalition of Labor Union Women: Metro-Detroit Chapter Records | 1974-1995 | | LR001614 |
| Coalition of Labor Union Women: San Francisco Chapter Records | 1974-1987 | | LR001332 |
| Coalition of Labor Union Women: Seattle Chapter Records | 1975-1976 | | LR000782 |
| Coalition of Black Trade Unionists Records | 1972-1995 | | LR001754 |
| Alton Cobb Papers | 1967-1968 | | LP000329 |
| Kenneth V. and Sheila M. Cockrel Papers | 1959-1999 | | UP001379 |
| Carl Cohen Papers | 1966-1974, bulk 1971-1974 | | UP000663 |
| David Cohen Papers | 1961-1967 | | LP000255 |
| Oscar Cohen Papers | 1946-49 | | UP000768 |
| Ronald Cohen Papers | 1948-1960 | | LP000717 |
| Sanford Cohl Papers | 1940 | | LP001047 |
| John Cole Papers | 1942 | | LP001487 |
| John and Phyllis Collier Papers | 1881-1975, bulk 1887-1948 | | LP000141 |
| Virgil Collins Papers | 1945-1946 | | LP000199 |
| Columbia Typographical Union No. 101 Records | 1815-1971 | | LR001577 |
| Committee for National Health Insurance Records | 1961-1988 | | LR001069 |
| Commonwealth College Records | 1932 | | LR001364 |
| Communications Workers of America District 4 Records | 1934-1979, bulk 1955-1975 | | LR000824 |
| Concerned Unionists Records | 1968-1971 | | LR000661 |
| Joseph P. Conlin Papers | 1965-1979 | | LP000737 |
| Edward Connor Papers | 1935-1966 | | UP000242 |
| John Conyers Sr. Papers | 1937-1945 | | LP000158 |
| Alexander Cook Papers | 1933-1934 | | LP001511 |
| Stanley Cook Papers | 1975 | | LP000785 |
| Wesley and Rita Cook Papers | 1941-1964 | | LP000676 |
| William Cook Papers | 1957 | | LP001138 |
| Cook County College Teachers Union, Local 1600 Records | 1966-2009 | | LR002098 |
| Elmer Cope Papers | 1945-1964 | | LP000931 |
| William Copeland Papers | 1965-1970 | | UP000273 |
| Minnie F. Corder Papers | 1971 | | LP000514 |
| Frank Cormier and William Eaton Papers | undated | | LP001099 |
| Edward Cote Papers | 1937-1948 | | LP000046 |
| Father Charles Coughlin FBI Files | 1936-1974, bulk 1942-1944 | | UP001842 |
| Andrew Court Papers | 1940-1966 | | LP001299 |
| Leon Cousens Papers | 1932-1937 | | LP000069 |
| James G. Couser Papers | 1946-1949 | | LP000030 |
| Covington Hall Papers | undated | | LP000174 |
| Richard W. and Constance Cowen Papers | 1975 | | LP000924 |
| John Craft Papers | 1945-1977 | | LP000965 |
| Roger Craig Papers | 1965-1970 | | UP000306 |
| Harold Cranefield Papers | 1932-1966 | | LP000595 |
| Ellen Creager Papers | 1995-1998, bulk 1995-1996 | | LP002361 |
| George Crockett Papers | 1944-1995 | | UP000276 |
| Alexander Crosby Papers | 1941-1942 | | LP001125 |
| Jack Crosby Papers | 1899-1932 | | LP000326 |
| James D. Crowe Papers | 1937-1938 | | LP000833 |
| Gloster Current Papers | 1942-1944 | | UP000382 |
| John J. D'Agostino Papers | 1950-1981, bulk 1951-1973 | | LP000032 |
| Franz E. Daniel Papers | 1890-1976 | | LP000600 |
| Sol A. Dann Papers | 1933-1970 | | UP000399 |
| Elvin Davenport Papers | 1942-1991, bulk 1942-1977 | | UP002362 |
| Hugh M. Davis, Jr. Papers | 1968-1990 | | UP001881 |
| William C. Davis Papers | 1931-1972, bulk 1964-1972 | | LP000547 |
| Everett "Pudge" Dawsen Papers | 1943-1968, bulk 1955-1968 | | LP002344 |
| Walter Day Papers | 1933-1962 | | LP000103 |
| Len and Caroline DeCaux Papers | 1925-1970 | | LP000832 |
| Angelo Deitos Papers | 1961-1981 | | |