| James Clerk Maxwell | 1831–1879 | 2 |
| M. H. (Mary H.) Maxwell | 1815–1891 | 1 |
| W. B. (William Babington) Maxwell | 1866–1938 | 1 |
| Maxwell, William Edward, Sir | 1846–1897 | 1 |
| J. Lewis (James Lewis) May | 1873–1961 | 4 |
| Karl May | 1842–1912 | 4 |
| Robert May | born 1588 | 1 |
| Samuel May | 1810–1899 | 1 |
| Sophie May | 1833–1906 | 16 |
| Brantz Mayer | 1809–1879 | 1 |
| Henry Mayer | 1868–1954 | 1 |
| A. L. (Anthony Lawson) Mayhew | 1842–1916 | 1 |
| Rutherford Mayne | 1878–1967 | 1 |
| Arthur Maynwaring | 1668–1712 | 1 |
| Margaret Mayo | 1882–1951 | 2 |
| O. C. (Oswald Chettle) Mazengarb | 1890–1963 | 1 |
| Giuseppe Mazzini | 1805–1872 | 1 |
| R. D. (Roelof Daniel) Mc Donald | 1873–1949 | 1 |
| Cleland Boyd McAfee | 1866–1944 | 1 |
| D. R. (David Russell) McAnally | 1847–1909 | 1 |
| Neil McBeath | 1893–1980 | 1 |
| Jasper Leonidas McBrien | born 1867 | 1 |
| James Dabney McCabe | 1842–1883 | 3 |
| Joseph McCabe | 1867–1955 | 4 |
| Sidney McCall | 1865–1954 | 1 |
| Henry McCarter | 1864–1942 | 1 |
| Margaret Hill McCarter | 1860–1938 | 2 |
| Carlton McCarthy | 1847–1936 | 1 |
| Justin McCarthy | 1830–1912 | 6 |
| Justin H. (Justin Huntly) McCarthy | 1860–1936 | 6 |
| J. T. (James Thompson) McCleary | 1853–1924 | 1 |
| M. G. (Mary Greenway) McClelland | 1853–1895 | 1 |
| James H. McClintock | 1864–1934 | 1 |
| Nellie L. McClung | 1873–1951 | 6 |
| Alexander K. (Alexander Kelly) McClure | 1828–1909 | 1 |
| John William McClymonds | born 1848 | 1 |
| J. Francis McComas | 1911–1978 | 1 |
| William McCombie | 1805–1880 | 1 |
| John Ludlum McConnel | 1826–1862 | 1 |
| Francis John McConnell | 1871–1953 | 1 |
| James R. (James Rogers) McConnell | 1887–1917 | 1 |
| Thomas J. (Thomas Joseph) McCormack | 1865–1932 | 1 |
| Elizabeth McCracken | born 1876 | 1 |
| John McCrae | 1872–1918 | 1 |
| Johnston McCulley | 1883–1958 | 1 |
| George Barr McCutcheon | 1866–1928 | 25 |
| John T. (John Tinney) McCutcheon | 1870–1949 | 3 |
| Etta Blaisdell McDonald | 1872–1963 | 2 |
| McDonnell, Michael, Sir | 1882–1956 | 1 |
| William McDougall | 1871–1938 | 1 |
| John McElroy | 1846–1929 | 6 |
| Elizabeth A. (Elizabeth Apthorp) McFadden | 1875–1961 | 1 |
| John Edgar McFadyen | 1870–1933 | 1 |
| J. C. (James Calvin) McFeeters | 1848–1928 | 1 |
| Thomas D'Arcy McGee | 1825–1868 | 3 |
| W J McGee | 1853–1912 | 1 |
| C. F. (Charles Fayette) McGlashan | 1847–1931 | 1 |
| John McGovern | 1850–1917 | 2 |
| Richard McGowan | born 1958 | 1 |
| Duncan McGregor | 1787–1881 | 1 |
| Alexander H. (Alexander Hamilton) McGuffey | 1816–1896 | 1 |
| William Holmes McGuffey | 1800–1873 | 9 |
| Elizabeth McGuire | born 1879 | 1 |
| John J. (John Joseph) McGuire | 1917–1981 | 5 |
| Jean N. (Jean Newton) McIlwraith | 1859–1938 | 1 |
| Maria J. (Maria Jane) McIntosh | 1803–1878 | 1 |
| John T. (John Thomas) McIntyre | 1871–1951 | 1 |
| Thomas Jefferson McKee | 1840–1899 | 1 |
| Fred A. (Fred Arthur) McKenzie | 1869–1931 | 1 |
| Frank McKernan | 1861–1934 | 1 |
| John McKinlay | 1819–1872 | 1 |
| Albert E. (Albert Edward) McKinley | 1870–1936 | 1 |
| William McKinley | 1843–1901 | 3 |
| J. Fairfax (James Fairfax) McLaughlin | 1839–1903 | 1 |
| Marie L. McLaughlin | born 1842 | 1 |
| John McLean | 1799–1890 | 2 |
| John McLenan | 1827–1866 | 1 |
| James McMahon | 1856–1922 | 1 |
| Blanche McManus | 1869–1935 | 1 |
| Thomas McManus | 1834–1914 | 1 |