| IWW Records | 1903-1996 | | LR000130 |
| IWW Detroit/Ann Arbor Branch Records | 1973-1982 | | LR000948 |
| IWW Minneapolis Branch Records | 1905-1971 | | LR000580 |
| IWW San Francisco Bay Area Branch Records | 1922-1981 | | LR001129 |
| Joseph Jablonower Papers | 1936-1968 | | LP000403 |
| JCA Adat Shalom Records | 1940-1975 | | UR001692 |
| JCA Benyas Photographic Negatives | 1950-1996 | | UR001749 |
| JCA Birmingham Temple Records | 1960s-2003 | | UR001827 |
| JCA Detroit Jewish Newspapers | 1901-1911, 1916-1951 | | UR001743 |
| JCA Jewish Association for Retarded Citizens Records | 1969-1994 | | UR001521 |
| JCA Jewish Community Council Records | 1937-1984 | | UR001726 |
| JCA Jewish Federation of Metropolitan Detroit Records | 1899-1990 | | UR001491 |
| JCA Jewish Home for the Aged Records | 1930-1993, bulk 1970-1990 | | UR001697 |
| JCA Mizrachi Records | 1960-1975 | | UR001696 |
| JCA National Council of Jewish Women: Detroit Section Records | 1891-1993 | | UR001647 |
| JCA Sholem Aleichem Institute Records | 1926-1996, bulk 1950-1970 | | UR001691 |
| JCA Leonard Simons Papers | 1872-1995, bulk 1940-1986 | | UP001518 |
| JCA Sinai Hospital Guild Records | 1952-2000 | | UR001748 |
| JCA Sinai Hospital Records | 1900-1999 | | UR001813 |
| JCA Philip Slomovitz Papers | 1919-1991 | | UP001494 |
| JCA Small Collections | 1867-2003 | | UR001812 |
| Mildred Jeffrey Papers | 1920s-2004 | | LP000300 |
| Newman Jeffrey Papers | 1820-1990 | | LP000173 |
| Richard Jensen Papers | 1968-1975 | | LP000893 |
| Jewish Labor Committee Records | 1947-1973, bulk 1955-1970 | | LR000150 |
| Edgar G. Johnston Papers | 1943-1966 | | LP000367 |
| Robert and Margaret Johnston Records | 1947-1959 | | UP001003 |
| Joint Committee on Library Service to Labor Groups Records | 1946-1966, bulk 1948-63 | | LR000229 |
| John Jurkanin Papers | circa 1930-1989 | | LP001372 |
| Jack Kadish Papers | 1942-1965 | | LP000162 |
| Anthony Kaiser Papers | 1946-1979 | | LP000652 |
| Robert Kanter Papers | 1939-1947 | | LP000195 |
| Raymond Kay Papers | 1944-1960 | | LP000852 |
| Damon J. Keith Papers | circa 1938-2007 | | UP001582 |
| Rachel Boone Keith Papers | 1937-2007, bulk 1970-2006 | | UP002117 |
| Samuel Kellman Papers | 1918-1954 | | UP000890 |
| Charles F. Kellogg Papers | 1955-1967 | | UP001419 |
| Maurice Kelman Papers | 1951-1997, bulk 1968-1974 | | UP001282 |
| William and Ann Kemsley Papers | 1943-1961 | | LP000943 |
| Casper P. Kenny Papers | 1944-1948 | | LP000183 |
| Kenosha Labor Records | 1933-1966 | | LR000307 |
| Monsignor Clement Kern Papers | 1945-1969, bulk 1945-1950 | | LP001013 |
| Lyman D. Ketchum Papers | 1971-1976 | | LP000765 |
| Vernon E. Keye Papers | 1946-1963 | | WSP000553 |
| Charles F. Kincaid Papers | 1941-1968 | | LP000381 |
| L. Bruce Kingery Papers | 1946-1974 | | LP000149 |
| William Kircher Papers | 1966-1973 | | LP000606 |
| L. K. Kirk Papers | 1933 | | LP000226 |
| Harvey Kitzman Papers | 1937-1960 | | |
| David Y. Klein Papers | 1960-1970 | | LP000873 |
| Dr. Shmarya Kleinman Papers | 1944-1962 | | UP000022 |
| Rose Kleinman: Greater Detroit Fair Housing Records | 1958-1972 | | UP000397 |
| Matt Kobe Papers | 1914-1921 | | LP000148 |
| Lucien Koch Papers | 1938-1965, bulk 1948-1952 | | LP000543 |
| Raymond Koch and Charlotte Moskowitz Papers | 1925-1982 | | LP000996 |
| E. H. Kohlhagen Papers | 1975 | | LP000771 |
| Alex Kovacs Papers | 1941-1996, bulk 1987-1996 | | LP001652 |
| Joseph J. Kowalski Papers | 1958-1967 | | UP000250 |
| Leo Kramer Papers | 1931-1969 | | LP001318 |
| Jay B. Krane Papers | 1948-1961 | | LP000614 |
| Dorothy Kraus Papers | 1920s-1990s, bulk 1930s-1960s | | LP001221 |
| Henry Kraus Papers | 1926-1960, bulk 1935-1944 | | LP000112 |
| Samuel Krieger Papers | 1926-1994 | | LP001616 |
| Maynard Krueger Papers | 1938 | | LP001075 |
| Frank LaBita Papers | 1953-1955 | | LP000044 |
| Labor Committee for Safe Energy and Full Employment Records | 1979-1981, bulk 1981 | | LR001131 |
| Labor Notes Records | 1973-1989 | | LR001555 |
| Labor Today Records | 1969-1975 | | LR000705 |
| Labor's Non-Partisan League Records | 1938-1942 | | LR000119 |
| James Lafferty Papers | 1969-1991 | | UP000626 |
| Lamphere Federation of Teachers Local 1614 Records | 1973-1998, bulk 1980-1985 | | LR002131 |
| Lloyd Lampher Papers | 1950-1976, bulk 1952-1976 | | LP001092 |
| Lily Lampinen Papers | 1960-1975 | | UP000836 |
| Layle Lane Papers | 1940-1969 | | LP000439 |
| Garland Lane Papers | 1964-1974 | | UP000309 |
| Charles Lang Papers | 1947-1971, bulk 1960-1967 | | LP000807 |
| Milton Lapine Papers | 1934-1983 | | LP001124 |
| E.W. Latchem Papers | 1915-1959 | | LP000171 |
| W. Jett Lauck Papers | 1913, 1926, 1935-1947 | | LP000409 |
| Robert Lee Lawson Paper | 1957 | | LP000117 |
| Daniel J. Leab Papers | 1900-1975 | | LP000590 |
| League for Mutual Aid Records | 1920-1972, bulk 1940-1972 | | LR000455 |
| League of Women Voters of Detroit Records | 1979-1980 | | UR001402 |
| Arthur F. Lederle Papers | 1914-1967 | | UP000559 |
| Abraham Lefkowitz Papers | 1934-1966, bulk 1934-1955 | | LP000402 |
| Ben Legere Papers | 1906-1970 | | LP000709 |
| Richard T. Leonard Papers | 1940-1971 | | LP000746 |
| Harry E. Lester Papers | 1980-1981 | | LP001035 |
| Marjorie Jackson Levin Papers | 1970-1973 | | UP000828 |
| Sander M. Levin Papers | 1960-1982 | | UP000515 |
| Edward Levinson Papers | 1910-1945 | | LP000085 |
| John L. Lewis Papers | 1879-1969 | | LR000494 |
| Stephen Lighthill Film Collection | 1979-1980 | | UAV001622 |
| James Lindahl Papers | 1930s-1950s | | LP001061 |
| Herbert Lindberg Papers | 1940-1943 | | LP000933 |
| C. Z. Lindsey Papers | 1942-1961 | | LP000534 |
| Henry Richardson Linville Papers | 1912-1941 | | LP000373 |
| Howard Lipton Papers | 1956-1971 | | LP000464 |
| Ed Liska Papers | 1962-1972 | | LP001469 |
| Viola Liuzzo Papers | 1953-1998, bulk 1965-1983 | | UP01745 |