- L. C. Angle, Jr., Collection, 1860/20013
- L. Claire Kincannon theatre collection, 1941/201517
- L. S. Rhodes & Sons Papers, 1886/19231
- Labor History Collection of Publications and Artifacts, 1937/19593
- Ladwig Family Papers, 1870/19595
- Lady Nancy Astor Papers, 1927/19563
- Laila W. Pearsall Personal Papers (SC-10)5
- Laine family papers, 1772/19614
- Land Grants, 1749/19851
- Land Records of the MVLA, 1858/20064
- Landmarks Society of Alexandria, Virginia Collection (MS079), 1934/19761
- Lane Carlson papers, 1937/197223
- Larry Jones, Collector, Postcards, Photographs, and Other Material, 1785/1993, bulk 1897/19931
- Larry McBryde Collection on the John McLaren McBryde Family, 1859/20132
- Larry R. Huffman papers, 1919/19594