Name
- Lucy, Charles, artist1
- MacColl, Norman, Editor 'The Athenaeum'1
- Mackay, Donald James, 11th Baron Reay1
- Macmillan and Co, publishers, 1843-1
- Macmillan, Alexander, of Macmillan and Co publishers1
- Mallet, Louis, of the Board of Trade and (1874-1883) of the India Office; Knight 18681
- Marquiset, Alfred, French writer1
- Martel de Janville, Sibylle Gabrielle Marie Antoinette, Comtesse de Mirabeau-Martel, alias 'Gyp', French novelist1
- Masters, Maxwell Tylden, FRS, botanist1
- May, Thomas Erskine, 1st Baron Farnborough, clerk of the House of Commons, 1815-18861
- Menabrea, Luigi Federigo, Count Marchese di Val Dora, Italian Ambassador in London1
- Miller, Cincinnatus Hiner al. Joaquin, American author1
- Milner-Gibson, Jasper Joseph, soli of T Milner-Gibson, MP1
- Milner-Gibson, Oliver Francis, brother of Jasper Joseph Milner-Gibson1
- Milner-Gibson, Susanna Arethusa, mother of Jasper Joseph Milner-Gibson1
- Milner-Gibson, Sydney Isabella, daughter of Thomas Milner-Gibson1
- Moret y Prendergast, Segismundo, Spanish Ambassador in London; Prime Minister of Spain 19051
- Moulton, John Fletcher, FRS1
- Mundella, Anthony John, PC, MP1
- Murdoch, James Gordon, of Kensington1