- MUSC College of Pharmacy Class Photos9
- Malloy Family Papers, 1861-19076
- Mamie E. Garvin Fields Papers, 1894 - 198786
- Marguerite Andell Collection, 1919-19465
- Mary Lamboll Thomas Beach Papers, 1822-189018
- Mary Motte Alston Pringle Receipt Book19
- Maxcy Gregg Papers, 1835-1888.2
- Mazyckborough-Wraggborough Photograph Survey37
- McLeod Family Papers, 1873-1990 (bulk 1900-1965)727
- McLeod Plantation Cemetery Collection1
- Medical Society of South Carolina Collection1
- Medical Society of South Carolina Digital Collections80
- Medical University of South Carolina Board of Trustees Collection, 1824-201277
- Medical University of South Carolina University Bulletins, 1878-2002182
- Middleton Papers, 1775-18154
- Midlands Memories2
- Millbrook account, n.d.1
- Minutes of the Annual Conferences of the Baptist, Episcopal, Lutheran, Methodist, and Presbyterian Churches in South Carolina, 1785-192083
- Miriam DeCosta Seabrook and Herbert U. Seabrook Papers, 1882-199556
- Nathaniel Russell Middleton Papers, 1823-18814