The Princeton University Library has very significant holdings of medieval and Renaissance manuscripts, Western European documents that date from the 11th-16th centuries. Most of them are in the Department of Rare Books and Special Collections, including 172 in the Robert Garrett Collection, 58 in the Grenville Kane Collection, 19 in the Robert Taylor Collection, and 201 in the growing Princeton Collection of Medieval and Renaissance Manuscripts. In addition, there are a number of manuscripts in the Cotsen Library, other manuscripts in other manuscript series or bound with printed books; more than 250 separate miniatures, leaves, and cuttings; and about 100 manuscripts in the Scheide Library.

Princeton's manuscripts range in date from the 8th to 16th centuries. While Latin texts are predominant, there are excellent holdings of Byzantine and post-Byzantine Greek manuscripts, and vernacular manuscripts in Middle English, French, Italian, Spanish, German, and Dutch or Flemish.

Digital versions of a number of manuscripts are available online. Among these is Princeton MS. 173, a late 13th-century Byzantine manuscript from Constantinople, containing Aristotle, Organon, with extensive annotations and diagrams added during the Paleologan Renaissance, 1259-1448.

Byzantine manuscripts are described and illustrated in Greek Manuscripts at Princeton: A Descriptive Catalogue by Sofia Kotzabassi and Nancy Sevcenko, with the assistance of Don C. Skemer (Department of Art and Archeology and the Program in Hellenic Studies, in association with Princeton University Press, 2010). This catalog covers the holdings of the Manuscripts Division, The Scheide Library, the Princeton University Art Museum, and the Princeton Theological Seminary.

For descriptions of Armenian manuscripts at Princeton, see Avedis K. Sanjian, A Catalog of Medieval Armenian Manuscripts in the United States (Berkeley: University of California Press, 1976), pp. 392-432.

The Department of Rare Books and Special Collections maintains the Checklist of Western Medieval, Byzantine, and Renaissance Manuscripts in the Princeton University Library and the Scheide Library. The checklist is intended to serve as a guide to available cataloging, textual and codicological descriptions, and digital images for western medieval, Byzantine, and Renaissance manuscripts in the Princeton University Library, including the Scheide Library, whose bequest to Princeton was announced in February 2015. Manuscripts are listed by holding unit, collection, and manuscript number or shelfmark. Links are given for more than well over 2,000 digital images of miniatures, illustrations, and selected diagrams and decoration in the manuscripts, about a third of which are illuminated.