Former Owner
- L’Art Ancien1
- Maggs Bros Ltd4
- Maksymilian Mielzynski1
- Mannheimer Hofbibliothek1
- Marchese Linterno2
- Margaret Anna Hazard1
- Marie-François Duchesne de Beaumanoir2
- Martin Schøyen1
- Marvin-L. Colker1
- Mary Bloch1
- Mary W. T. Dickinson2
- Mayfair Rare Books and Manuscripts1
- Maḥmūd al-Ustādār, d. 1396 or 71
- McCormick Theological Seminary1
- Menaḥem Naḥum, ha-Leṿi, mi-ḳ.ḳ. Dribin1
- Michael Greenberg1
- Michael Tomkinson1
- Milton Fischmann3
- Monastery of Saint Peter (Erfurt, Germany)1
- Morton Davis Mitchell1