Former Owner
- Luigi Arrigoni1
- Luigi Cora1
- Luis Ordoñez1
- Luther Albertus Brewer1
- Lutheran Theological Seminary at Philadelphia1
- Lydia Thompson Morris3
- M. Louise Stowell1
- Maggs Bros Ltd5
- Maksymilian Mielzynski1
- Mannheimer Hofbibliothek1
- Marcantonio Contarini1
- Marchese Linterno1
- Margaret Le Seigneur1
- Marguerite of Lorraine1
- Maria Riddell1
- Marie-François Duchesne de Beaumanoir1
- Martin Breslauer1
- Menno Hertzberger1
- Mercantile Library Company1
- Messieurs Du Trieu2