Former Owner
- Madeleine Cosman1
- Madyājñika Devakṛṣṇa1
- Mahdī ibn Muṣṭafá al-Ḥusaynī1
- Maheśa1
- Malachia Ormanian1
- Malvezzi de' Medici1
- Manookjee Sorabjee Ashburner1
- Manuel Fernández del Castillo1
- Manūchihr Nukhastīn Āṣaf Qājār1
- Margaret Barclay Wilson1
- Maria Riddell1
- Marie Cleophe de Sollario1
- Marie de Albano1
- Marienstiftsgymnasium1
- Markus Fugger1
- Marquis of Astorga1
- Marsden J. Perry1
- Mary Augusta Strachey1
- Mary Lusher1
- Mary Shalom Karo1