{|class="wikitable sortable"
|-
! Senator !! Lifespan !! Party !! Prov. !! Entered !! Left !! Appointed by !! Left due to !! For life?
|-
| Jane MacAdam || 1957–present || || PE || 3 May 2023 || — || Trudeau, J. || — ||
|-
| Creelman MacArthur || 1874–1943 || L || PE || 5 September 1925 || 27 December 1943 || King || Death || Y
|-
| Andrew Archibald Macdonald || 1829–1912 || LC || PE || 11 May 1891 || 21 March 1912 || Macdonald || Death || Y
|-
| Finlay Macdonald || 1923–2002 || PC || NS || 21 December 1984 || 4 January 1998 || Mulroney || Retirement ||
|-
| John Macdonald || 1824–1890 || IL || ON || 9 November 1887 || 4 February 1890 || Macdonald || Death || Y
|-
| John Alexander Macdonald || 1883–1945 || C || NS || 2 March 1932 || 11 June 1945 || Bennett || Death || Y
|-
| John Alexander Macdonald || 1874–1948 || C || PE || 20 July 1935 || 15 November 1948 || Bennett || Death || Y
|-
| John Joseph MacDonald || 1891–1986 || PC || PE || 27 January 1958 || 20 April 1971 || Diefenbaker || Resignation || Y
|-
| John Michael Macdonald || 1906–1997 || PC || NS || 24 June 1960 || 20 June 1997 || Diefenbaker || Death || Y
|-
| Michael L. MacDonald || 1955–present|| C || NS || 2 January 2009 || — || Harper || — ||
|-
| William John Macdonald || 1832–1916 || C || BC || 13 December 1871 || 13 April 1915 || Macdonald || Resignation || Y
|-
| William Ross Macdonald || 1891–1976 || L || ON || 12 June 1953 || 22 December 1967 || St. Laurent || Voluntary retirement || Y
|-
| Angus Claude Macdonell || 1861–1924 || C || ON || 1 August 1917 || 1 January 1921 || Borden || Resignation || Y
|-
| Archibald Hayes Macdonell || 1868–1939 || C || ON || 7 November 1921 || 12 November 1939 || Meighen || Death || Y
|-
| Allan MacEachen || 1921–2017 || L || NS || 29 June 1984 || 6 July 1996 || Trudeau, P. || Retirement ||
|-
| Alexander Macfarlane || 1818–1898 || C || NS || 10 October 1870 || 14 December 1898 || Macdonald || Death || Y
|-
| Donald MacInnes || 1824–1900 || L || ON || 24 December 1881 || 2 December 1900 || Macdonald || Death || Y
|-
| Robert Mackay || 1840–1916 || L || QC || 21 January 1901 || 25 December 1916 || Laurier || Death || Y
|-
| William MacKay || 1847–1915 || C || NS || 20 November 1912 || 8 November 1915 || Borden || Death || Y
|-
| David MacKeen || 1839–1916 || C || NS || 21 February 1896 || 15 October 1915 || Bowell || Resignation || Y
|-
| Ian Alistair Mackenzie || 1890–1949 || L || BC || 19 January 1948 || 2 September 1949 || King || Death || Y
|-
| Norman MacKenzie || 1894–1986 || IL || BC || 24 February 1966 || 5 January 1969 || Pearson || Retirement ||
|-
| James Angus MacKinnon || 1881–1958 || L || AB || 9 May 1949 || 18 April 1958 || St. Laurent || Death || Y
|-
| Donald MacLennan || 1877–1953 || L || NS || 29 January 1940 || 19 October 1953 || King || Death || Y
|-
| Alan Macnaughton || 1903–1999 || L || QC || 8 July 1966 || 30 July 1978 || Pearson || Retirement ||
|-
| David Lewis Macpherson || 1818–1896 || C || ON || 23 October 1867 || 16 August 1896 || Royal proclamation || Death || Y
|-
| Heath MacQuarrie || 1919–2002 || PC || PE || 3 October 1979 || 18 September 1994 || Clark || Retirement ||
|-
| Duncan Kenneth MacTavish || 1899–1963 || L || ON || 11 June 1963 || 15 November 1963 || Pearson || Death || Y
|-
| Shirley Maheu || 1931–2006 || L || QC || 1 February 1996 || 1 February 2006 || Chrétien || Death ||
|-
| Frank Mahovlich || 1938–present|| L || ON || 11 June 1998 || 10 January 2013 || Chrétien || Retirement ||
|-
| Charles-Christophe Malhiot || 1808–1874 || L || QC || 23 October 1867 || 9 November 1874 || Royal proclamation || Death || Y
|-
| Marian Maloney || 1924–2010 || L || ON || 11 June 1998 || 16 August 1999 || Chrétien || Retirement ||
|-
| Ghislain Maltais || 1944–present|| C || QC || 6 January 2012 || 22 April 2019 || Harper || Retirement ||
|-
| Ernest Manning || 1908–1996 || SC || AB || 7 October 1970 || 20 September 1983 || Trudeau, P. || Retirement ||
|-
| rowspan="2" | Fabian Manning || rowspan="2" | 1964–present|| rowspan="2" | C || rowspan="2" | NL || 22 December 2008 || 28 March 2011 || rowspan="2" | Harper || Resigned || rowspan="2" |
|-
|25 May 2011
|—
|—
|-
| Jean Marchand || 1918–1988 || L || QC || 9 December 1976 || 15 December 1983 || Trudeau, P. || Resignation ||
|-
| Leonard Marchand || 1933–2016 || L || BC || 29 June 1984 || 1 March 1998 || Trudeau, P. || Resignation ||
|-
| Arthur Marcotte || 1873–1958 || C || SK || 6 July 1931 || 18 August 1958 || Bennett || Death || Y
|-
| Lorna Marsden || 1942–present|| L || ON || 24 January 1984 || 31 August 1992 || Trudeau, P. || Resignation ||
|-
| Duncan Marshall || 1872–1946 || L || ON || 20 January 1938 || 16 January 1946 || King || Death || Y
|-
| Elizabeth Marshall || 1951–present|| C || NL || 29 January 2010 || — || Harper || — ||
|-
| Jack Marshall || 1919–2004 || PC || NL || 23 March 1978 || 26 November 1994 || Trudeau, P. || Retirement ||
|-
| Paul Martin Sr. || 1903–1992 || L || ON || 20 April 1968 || 30 October 1974 || Trudeau, P. || Resignation ||
|-
| Peter Francis Martin || 1856–1935 || C || NS || 5 December 1921 || 2 May 1935 || Meighen || Death || Y
|-
| Yonah Martin || 1965–present|| C || BC || 2 January 2009 || —|| Harper || — ||
|-
| Sabi Marwah || 1951–present|| NA || ON || 10 November 2016 || 7 September 2023 || Trudeau, J. || Resignation ||
|-
| James Mason || 1843–1918 || C || ON || 26 May 1913 || 16 July 1918 || Borden || Death || Y
|-
| Paul Massicotte || 1951–present|| L || QC || 26 June 2003 || — || Chrétien || — ||
|-
| rowspan="2" | Louis-Rodrigue Masson || rowspan="2" | 1833–1903 || rowspan="2" | C || rowspan="2" | QC || 29 September 1882 || 6 November 1884 || rowspan="2" | Macdonald || rowspan="2" | Resignation || rowspan="2" | Y
|-
|3 February 1890
|11 June 1903
|-
| Roderick Matheson || 1793–1873 || C || ON || 23 October 1867 || 13 January 1873 || Royal proclamation || Death || Y
|-
| Marnie McBean || 1968–present || || ON || 20 December 2023 || — || Trudeau, J. || — ||
|-
| Alexander McCall || 1844–1925 || C || ON || 26 May 1913 || 10 June 1925 || Borden || Death || Y
|-
| Lachlin McCallum || 1823–1903 || LC || ON || 4 February 1887 || 13 January 1903 || Macdonald || Death || Y
|-
| Mary Jane McCallum || 1952–present|| || MB || 4 December 2017 || — || Trudeau, J. || — ||
|-
| Abner Reid McClelan || 1831–1917 || L || NB || 23 October 1867 || 9 December 1896 || Royal proclamation || Resignation || Y
|-
| Archibald McCoig || 1873–1927 || L || ON || 4 January 1922 || 21 November 1927 || King || Death || Y
|-
| John Mccormick || 1858–1936 || C || NS || 21 September 1921 || 21 February 1936 || Meighen || Death || Y
|-
| Elaine McCoy || 1946–2020 || PC→IPC→NA || AB || 24 March 2005 || 29 December 2020 || Martin || Death ||
|-
| Walter McCrea || 1810–1892 || L || ON || 23 October 1867 || 5 January 1871 || Royal proclamation || Resignation || Y
|-
| Jonathan McCully || 1809–1877 || L || NS || 23 October 1867 || 28 September 1870 || Royal proclamation || Resignation || Y
|-
| Wallace McCutcheon || 1906–1969 || PC || ON || 9 August 1962 || 13 May 1968 || Diefenbaker || Resignation || Y
|-
| Alexander Hamilton McDonald || 1919–1980 || L || SK || 13 August 1965 || 31 March 1980 || Pearson || Death ||
|-
| Charles McDonald || 1867–1936 || L || BC || 30 December 1935 || 6 October 1936 || King || Death || Y
|-
| Donald McDonald || 1816–1879 || L || ON || 23 October 1867 || 20 January 1879 || Royal proclamation || Death || Y
|-
| John Alexander McDonald || 1889–1962 || L || NS || 18 April 1945 || 16 April 1962 || King || Death || Y
|-
| John Anthony McDonald || 1875–1948 || I || NB || 17 February 1921 || 12 December 1948 || Meighen || Death || Y
|-
| William McDonald || 1837–1916 || C || NS || 12 May 1884 || 4 July 1916 || Macdonald || Death || Y
|-
| Wilfrid Laurier McDougald || 1881–1942 || L || QC || 25 June 1926 || 3 May 1932 || King || Resignation || Y
|-
| Charles McElman || 1920–2000 || L || NB || 24 February 1966 || 1 April 1990 || Pearson || Resignation ||
|-
| Gerry McGeer || 1888–1947 || L || BC || 9 June 1945 || 11 August 1947 || King || Death || Y
|-
| Frederic McGrand || 1895–1988 || L || NB || 28 July 1955 || 22 January 1988 || St. Laurent || Resignation || Y
|-
| James Drummond McGregor || 1838–1918 || L || NS || 24 April 1903 || 1 October 1910 || Laurier || Resignation || Y
|-
| William Henry McGuire || 1875–1957 || L || ON || 20 December 1926 || 31 October 1957 || King || Death || Y
|-
| George McHugh || 1845–1926 || L || ON || 21 January 1901 || 28 November 1926 || Laurier || Death || Y
|-
| George McIlraith || 1908–1992 || L || ON || 27 April 1972 || 29 July 1983 || Trudeau, P. || Retirement ||
|-
| Thomas Robert McInnes || 1840–1904 || I || BC || 24 December 1881 || 18 November 1897 || Macdonald || Resignation || Y
|-
| Tom McInnis || 1945–present|| C || NS || 6 September 2012 || 9 April 2020 || Harper || Retirement ||
|-
| James P. McIntyre || 1883–1957 || L || PE || 19 February 1943 || 8 April 1957 || King || Death || Y
|-
| Paul McIntyre || 1944–present|| C || NB || 6 September 2012 || 1 November 2019 || Harper || Retirement ||
|-
| Thomas McKay || 1839–1912 || LC || NS || 24 December 1881 || 13 January 1912 || Macdonald || Death || Y
|-
| Stanley McKeen || 1897–1966 || L || BC || 27 January 1947 || 1 December 1966 || King || Death || Y
|-
| George Crawford McKindsey || 1829–1901 || C || ON || 11 January 1884 || 12 February 1901 || Macdonald || Death || Y
|-
| Peter McLaren || 1833–1919 || C || ON || 21 February 1890 || 23 May 1919 || Macdonald || Death || Y
|-
| Alexander Neil McLean || 1885–1967 || L || NB || 18 April 1945 || 12 March 1967 || King || Death || Y
|-
| Donald A. McLean || 1907–1973 || L || NB || 15 March 1968 || 5 November 1973 || Pearson || Death ||
|-
| John McLean || 1846–1936 || C || PE || 3 December 1915 || 20 February 1936 || Borden || Death || Y
|-
| Archibald McLelan || 1824–1890 || LC || NS || 21 June 1869 || 20 May 1881 || Macdonald || Resignation || Y
|-
| John Stewart McLennan || 1853–1939 || C || NS || 10 February 1916 || 15 September 1939 || Borden || Death || Y
|-
| William McMaster || 1811–1887 || L || ON || 23 October 1867 || 22 September 1887 || Royal proclamation || Death || Y
|-
| Lendrum McMeans || 1859–1941 || C || MB || 26 July 1917 || 13 September 1941 || Borden || Death || Y
|-
| Donald McMillan || 1835–1914 || C || ON || 11 January 1884 || 26 July 1914 || Macdonald || Death || Y
|-
| James McMullen || 1833–1913 || L || ON || 11 February 1902 || 18 March 1913 || Laurier || Death || Y
|-
| John M. McNair || 1957–present || || NB || 31 October 2023 || — || Trudeau, J. || — ||
|-
| William Craig McNamara || 1904–1984 || L || MB || 7 October 1970 || 8 August 1979 || Trudeau, P. || Retirement ||
|-
| Marilou McPhedran || 1951–present|| NA || MB || 10 November 2016 || — || Trudeau, J. || — ||
|-
| Alexander Duncan McRae || 1874–1946 || C || BC || 4 September 1931 || 26 June 1946 || Bennett || Death || Y
|-
| Peter McSweeney || 1842–1921 || L || NB || 15 March 1899 || 2 February 1921 || Laurier || Death || Y
|-
| Marie-Françoise Mégie || 1950–present|| NA || QC || 25 November 2016 || — || Trudeau, J. || — ||
|-
| Arthur Meighen || 1874–1960 || C || ON || 2 March 1932 || 16 January 1942 || Bennett || Resignation || Y
|-
| Michael Meighen || 1939–present|| C || ON || 27 September 1990 || 6 February 2012 || Mulroney || Resignation ||
|-
| Terry Mercer || 1947–present|| L || NS || 7 November 2003 || 6 May 2022 || Chrétien || Retirement ||
|-
| Pana Merchant || 1943–present|| L || SK || 12 December 2002 || 31 March 2017 || Chrétien || Resignation ||
|-
| Léonce Mercier || 1926–2019|| L || QC || 9 August 1996 || 11 August 2001 || Chrétien || Retirement ||
|-
| Don Meredith || 1964–present|| C→NA || ON || 18 December 2010 || 10 May 2017 || Harper || Resignation ||
|-
| Samuel Merner || 1823–1908 || C || ON || 12 January 1887 || 11 August 1908 || Macdonald || Death || Y
|-
| Léon Méthot || 1895–1972 || PC || QC || 12 October 1957 || 6 August 1972 || Diefenbaker || Death || Y
|-
| Hervé Michaud || 1912–1978 || L || NB || 15 March 1968 || 5 June 1978 || Pearson || Death ||
|-
| Edward Michener || 1869–1947 || C || AB || 5 February 1918 || 16 June 1947 || Borden || Death || Y
|-
| William Miller || 1835–1912 || LC || NS || 23 October 1867 || 23 February 1912 || Royal proclamation || Death || Y
|-
| David Mills || 1831–1903 || L || ON || 13 November 1896 || 7 February 1902 || Laurier || Resignation || Y
|-
| Samuel Sylvester Mills || 1806–1874 || C || ON || 23 October 1867 || 24 January 1874 || Royal proclamation || Death || Y
|-
| John Milne || 1839–1922 || C || ON || 3 December 1915 || 4 March 1922 || Borden || Death || Y
|-
| Lorna Milne || 1934–2023 || L || ON || 21 September 1995 || 13 December 2009 || Chrétien || Retirement ||
|-
| Grant Mitchell || 1951–present|| L→IL→NA || AB || 24 March 2005 || 24 April 2020 || Martin || Resignation ||
|-
| Peter Mitchell || 1824–1899 || LC || NB || 23 October 1867 || 13 July 1872 || Royal proclamation || Resignation || Y
|-
| William Mitchell || 1851–1926 || L || QC || 5 March 1904 || 10 May 1926 || Laurier || Death || Y
|-
| Julie Miville-Dechêne || 1959–present|| || QC || 20 June 2018 || — || Trudeau, J. || — ||
|-
| Percy Mockler || 1949–present|| C || NB || 2 January 2009 || 13 April 2024 || Harper || Retirement ||
|-
| Gildas Molgat || 1927–2001 || L || MB || 7 October 1970 || 28 February 2001 || Trudeau, P. || Death ||
|-
| John Patrick Molloy || 1873–1948 || L || MB || 6 October 1925 || 16 March 1948 || King || Death || Y
|-
| Hartland Molson || 1907–2002 || I || QC || 28 July 1955 || 31 May 1993 || St. Laurent || Resignation || Y
|-
| Lucie Moncion || 1958–present|| NA || ON || 10 November 2016 || — || Trudeau, J. || — ||
|-
| Gustave Monette || 1887–1969 || PC || QC || 12 October 1957 || 23 December 1969 || Diefenbaker || Death || Y
|-
| Donald Montgomery || 1808–1893 || C || PE || 18 October 1873 || 31 July 1893 || Macdonald || Death || Y
|-
| Hippolyte Montplaisir || 1839–1927 || LC || QC || 9 February 1891 || 20 June 1927 || Macdonald || Death || Y
|-
| Rosemary Moodie || 1956–present|| || ON || 12 December 2018 || — || Trudeau, J. || — ||
|-
| Wilfred Moore || 1942–present|| L || NS || 26 September 1996 || 14 January 2017 || Chrétien || Retirement ||
|-
| Lucien Moraud || 1885–1951 || C || QC || 30 December 1933 || 29 May 1951 || Bennett || Death || Y
|-
| Pierre Moreau || 1957–present || || QC || 10 September 2024 || — || Trudeau, J. || — ||
|-
| Yves Morin || 1929–2024 || L || QC || 8 March 2001 || 28 November 2004 || Chrétien || Retirement ||
|-
| Oliver Mowat || 1820–1903 || L || ON || 15 July 1896 || 18 November 1897 || Laurier || Resignation || Y
|-
| Tracy Muggli || 1964/1965–present || || SK || 16 August 2024 || — || Trudeau, J. || — ||
|-
| Robert Muir || 1919–2011 || PC || NS || 26 March 1979 || 10 November 1994 || Trudeau, P. || Retirement ||
|-
| William Muirhead || 1819–1884 || L || NB || 4 January 1873 || 29 December 1884 || Macdonald || Death || Y
|-
| Robert Alexander Mulholland || 1860–1927 || C || ON || 12 March 1918 || 1 October 1927 || Borden || Death || Y
|-
| Henry Mullins || 1861–1952 || C || MB || 14 August 1935 || 5 September 1950 || Bennett || Resignation || Y
|-
| Jim Munson || 1946–present|| L || ON || 10 December 2003 || 14 July 2021 || Chrétien || Retirement ||
|-
| James Murdock || 1871–1949 || L || ON || 20 March 1930 || 15 May 1949 || King || Death || Y
|-
| Charles Murphy || 1862–1935 || L || ON || 5 September 1925 || 24 November 1935 || King || Death || Y
|-
| Edward Murphy || 1818–1895 || LC || QC || 30 May 1889 || 5 December 1895 || Macdonald || Death || Y
|-
| Patrick Charles Murphy || 1868–1925 || C || PE || 20 November 1912 || 6 March 1925 || Borden || Death || Y
|-
| Lowell Murray || 1936–present|| PC || ON || 13 September 1979 || 26 September 2011 || Clark || Retirement ||
|}