Former Owner
- Johannes Patou1
- John A. Savage Jr.1
- John Estmond1
- John Ives1
- John Lumley, 1st Baron Lumley1
- John M Cuthbert1
- Joseph Barrois1
- Joseph E. Widener1
- Josephine Widener Wichfield1
- Lawrence J. Schoenberg1
- Louis H. Silver1
- Léon Gruel1
- Mannheimer Hofbibliothek1
- Mary W. T. Dickinson1
- Matthew Simpson Parkhurst1
- Michaeliskonvent1
- Mikhail Golitsyn1
- Milton Fischmann1
- Monasterio de El Paular1
- Nathan Comfort Starr1