L
- Laboratory for Research on the Structure of Matter Financial Records (UPB 16.5)
- Lamb, Roswell G., Papers (UPT 50 L218)
- Law School History Exhibition for the Opening of Tannenbaum Hall Collection (UPG 65)
- Law School. Admissions (UPB 6.62)
- Law School. Alumni Materials (UPB 6.10)
- Law School. Bound Records (UPB 6.11)
- Law School. Bursars Materials (UPB 6.65)
- Law School. Committee Minutes and Records (UPB 6.2)
- Law School. Curriculum Records (UPB 6.8)
- Law School. Faculty Minutes (UPB 6.1)
- Law School. Fellowships and Scholarships (UPB 6.63)
- Law School. Grade Sheets and Record Cards (UPB 6.61)
- Law School. Health Law Project Records (UPB 6.9)
- Law School. Office of the Dean Records. Robert Mundheim Administration (UPB 6.41)
- Law School. Printed Materials, Forms, and Scrapbooks (UPB 6.3)
- Law School. Registration Materials (UPB 6.64)
- Law School. Secretary Records (UPB 6.43)
- Law School. Student Activities Records (UPB 6.7)
- Lenape Club Records (UPQ 1100)
- Lesbian Gay Bisexual Transgender Center at the University of Pennsylvania Records (UPE 502)
- Levy, Frank D., Memorabilia Collection (UPT 50 L668)
- Lewin, Moshe, Papers (UPT 50 L672)
- Lewis, William Draper, Papers (UPT 50 L667)
- Li, Hui-lin, Papers (UPT 50 L693)
- Lingelbach, William Ezra, Papers (UPT 50 L755)
- Lippincott Library Records (UPB 55.3)
- Lippincott, Horace Mather, Papers (UPT 50 L765)
- Locke, Howard Van, Collection (UPT 50 L814)
- Long, Crawford Williamson, Collection (UPT 50 L848)
- Longstreth, Walter C., Scrapbook (UPS 2 L857)
- Lowright, Wallace J., Papers (UPT 50 L921)
- Luehring, Frederick William, Papers (UPT 50 L926)
- Lukoff, Herman, Papers (UPT 50 L954)