Former Owner
- John Lee1
- John McRay1
- John Roland Abbey1
- John Ruskin1
- Joseph E. Widener1
- Lathrop Colgate Harper1
- Laurence William Hodson1
- Lawrence J. Schoenberg2
- Leo Olschki1
- Ludwig Rosenthal1
- Luigi Arrigoni1
- Maggs Bros Ltd2
- Maksymilian Mielzynski1
- Mannheimer Hofbibliothek1
- Marchese Linterno1
- Marie-François Duchesne de Beaumanoir1
- Mary W. T. Dickinson1
- Michael Tomkinson1
- Milton Fischmann3
- Morton Davis Mitchell1