- M. Caldwell Butler Papers, 1945/20061
- M. Rosaria Piomelli Architectural Collection, 1960/199516
- M. Rupert Cutler Papers, 1930/2021, bulk 1962/20215
- M. Thomas Inge papers, 1879/200110
- M.C. Wilhelm Medical History collection, 1959/19761
- M.H. Ross, Collector, Papers, 1930/19741
- MCV Foundation/Monumental Church records, 1957/19655
- Maakestad Collection, 1972/19842
- Mabel Hoggard, Educator, Papers, 1924/1989, bulk 1932/19891
- Maddex Family Papers, 1937/20001
- Madison E. Marye Papers, 1932/20076
- Magazines, 1836/18961
- Maggie Anderson, Poet, Papers, 1958/2017, bulk 1980/201221
- Malcolm Ater Papers, 1950/1974, bulk 1956/19661
- Malcolm Davis, Artist, Papers, 1970/20157