- Mears, J. Ewing (James Ewing), 1838-1918, author1
- Medical Association of the District of Columbia, author.2
- Medico-Chirurgical Hospital (Philadelphia, Pa.)1
- Mendeleyev, Dmitry Ivanovich, 1834-1907, author4
- Merck & Co.1
- Meyer, Henri, artist1
- Meyer, Willy, 1858-19321
- Meyer, Willy, 1858-1932, author1
- Méaulle, F. (Fortuné), b. 18441
- Michinard, P. (Paul), 1858-1925, author1
- Miller, John S., 1845-1922 author1
- Mills, Charles K. (Charles Karsner), 1845-19311
- Minor, James L., 1855- author1
- Minot, Charles Sedgwick, 1852-19141
- Mitchell, S. Weir (Silas Weir), 1829-19143
- Moncorvo, Arthur.1
- Morrill, F. Gordon, author1
- Morrissey, J. J., author1
- Morse, John Lovett, 1865-1940 author2
- Morton, Thomas G. (Thomas George), 1835-19031