•
Jules François Mabille (1831–1904) France •
Frank Mace MacFarland (1869–1951) United States, Hopkins Marine Biological Station at Pacific Grove •
William Macnae (1914–1975) South Africa. •
Virginia Orr Maes (1920–1986) United States, malacologist associated with the
Academy of Natural Sciences of Philadelphia •
August Wilhelm Malm (1821–1882) Sweden •
Hermann von Maltzan (1843–1891) Germany •
Katharina Mangold-Wirz (1922–2003) Switzerland •
Ernst Gustav Gotthelf Marcus (Ernesto) (1893–1968) Germany, Brazil, spouse of Eveline du Bois-Reymond Marcus •
Eveline Du Bois-Reymond Marcus (1901–1990) Germany, Brazil •
Bruce Marshall (1948–) New Zealand, taxonomist •
Patrick Marshall (1869–1950) New Zealand, geologist •
Eduard von Martens (1831–1904) Germany •
Friedrich Wilhelm Martini (1729–1778) Germany •
Thomas Martyn (1760–1816) England •
Annie Massy (1868–1931) Ireland •
Charles Johnson Maynard (1845–1929) United States •
J. C. McConnell (1844–1904) United States •
James Hamilton McLean (1936–) United States •
James Cosmo Melvill (1845–1929) United Kingdom •
Auguste Ménégaux (1857–1937) France •
Karl Theodor Menke (1791–1861) Germany •
Artie L. Metcalf (1929–2016) United States •
Friedrich Christian Meuschen (1719–1811) Germany •
Louis André Gaspard Michaud (1795–1880) France, malacologist, also known as Gaspard Michaud and as A. L. G. Michaud •
Jean-Louis Hardouin Michelin de Choisy (1786–1867) France •
Jesse Wedgwood Mighels (1795–1861) United States •
John Samuel Miller (1783–1873) United Kingdom •
Pierre-Aimé Millet (1783–1873) France •
Adolph Modéer (1738–1799) Sweden •
Otto Franz von Möllendorff (1848–1903) Germany, malacologist •
Hans Peter Christian Møller (1810–1845) Denmark/Greenland, author of
Index Molluscorum Grönlandiae •
Tommaso di Maria Allery Monterosato (1841–1927) Italy •
John Edmund Sharrock Moore (1870–1947) United Kingdom •
Otto Andreas Lowson Mörch (1828–1878) Sweden, Denmark, France •
Pierre Marie Arthur Morelet (1809–1892) France •
Edward Sylvester Morse (1838–1925) United States •
Johann Rudolf Albert Mousson (1805–1890) France, Switzerland •
Robert C. Murdoch (1861–1923) New Zealand ==N==