Former Owner
- Nicholas Chevalier1
- Nicholas Herry1
- Nicolai Briganti1
- Nicolas Fowle1
- Nicolas Rauch1
- Nicolaus de Monte Murro1
- Northwich Library1
- Notre-Dame de Macourt monastery1
- Notre-Dame monastery (Ambert, France)1
- Novalesa Abbey1
- O. A. Bump1
- Oettingen-Wallerstein library1
- Ohio State University Center for Epigraphical and Palaeographical Studies1
- Ohio State University School of Music1
- Oliver Henry Perkins1
- Omaha Public Library1
- Orlandus de Fatiis1
- Oswald Carl Friedrich von Seilern und Aspang1
- Otto Haas1
- Owen D. Young1