| No. | Mayor | Image | Term | Party | Notes |
|---|
| 1 | James D. Green | | May 1846 – April 1848 | | |
| 2 | Sidney Willard | | April 1848 – April 1851 | | |
| 3 | George Stevens | | April 1851 – April 1853 | | |
| 4 | James D. Green | | April 1853 – April 1854 | None | |
| 5 | Abraham Edwards | | April 1854 – January 1855 | | |
| 6 | Zebina L. Raymond | | January 1855 – January 1856 | | |
| 7 | John Sargent | | January 1855 – January 1860 | | |
| 8 | James D. Green | | January 1860 – July 24, 1861 | | |
| 9 | Charles Theodore Russell | | July 31, 1861 – January 1863 | | |
| 10 | George C. Richardson | | January 1863 – January 1864 | | |
| 11 | Zebina L. Raymond | | January 1864 – January 1865 | | |
| 12 | J. Warren Merrill | | January 1865 – January 1867 | | |
| 13 | Ezra Parmenter | | January 1867 – January 1868 | | |
| 14 | Charles H. Saunders | | January 1868 – January 1870 | | |
| 15 | Hamlin R. Harding | | January 1870 – January 1872 | | |
| 16 | Henry Oscar Houghton | | January 1872 – January 1873 | |
| 17 | Isaac Bradford | | January 1873 – January 1877 | Democratic | |
| 18 | Frank Augustus Allen | | January 1877 – January 1878 | | |
| 19 | Samuel L. Montague | | January 1878 – January 1880 | | |
| 20 | James Morris Whiton Hall | | January 1880 – January 1881 | | |
| 21 | James Augustus Fox | | January 1881 – January 1885 | | |
| 22 | William Russell | | January 1885 – January 1889 | Democratic | |
| 23 | Henry Gilmore | | January 1889 – January 1891 | |
| 24 | Alpheus B. Alger | | January 1891 – January 1892 | | |
| 25 | William Bancroft | | January 1893 – January 1897 | | |
| 26 | Alvin F. Sortwell | | January 1897 – January 1899 | | |
| 27 | Edgar R. Champlin | | January 1899 – January 1901 | Republican | |
| 28 | David T. Dickinson | | January 1901 – January 1902 | Republican | |
| 29 | John H. H. McNamee | | January 1902 – January 1904 | | |
| 30 | Augustine J. Daly | | January 1904 – January 1906 | | |
| 31 | Charles H. Thurston | | January 1906 – January 1907 | | |
| 32 | Walter C. Wardwell | | January 1907 – April 1909 | | |
| 33 | William F. Brooks | | April 1908 – April 1911 | | |
| 34 | J. Edward Barry | | April 1911 – April 1914 | | |
| 35 | Timothy W. Good | | April 1914 – January 3, 1916 | | |
| 36 | Wendell D. Rockwood | | January 3, 1916 – January 1918 | | |
| 37 | Edward W. Quinn | | January 1918 – January 1930 | Democratic | |
| 38 | Richard M. Russell | | January 1930 – January 1936 | Democratic | |
| 39 | John D. Lynch | | January 1936 – January 1938 | | |
| 40 | John W. Lyons | | January 1938 – July 22, 1941 | | |
| 41 | Francis C. Sennott | | July 23, 1941 – January 1, 1942 | | Last Mayor before the City Manager form of government was established under a Massachusetts Plan E Charter. |
| 42 | John H. Corcoran | | 1942 – December 28, 1945 | Democratic | Beginning of the weak Mayor/City Manager form of government |
| 43 | John D. Lynch | | 1946–1947 | | |
| 44 | Michael Neville | | 1948–1949 | | |
| 45 | Edward Crane | | 1950–1951 | | |
| 46 | Joseph DeGuglielmo | | 1952–1953 | | |
| 47 | John J. Foley | | 1954–1955 | | |
| 48 | Edward J. Sullivan | | 1956–1957 | | |
| 49 | Tom McNamara | | 1958–1959 | | |
| 50 | Edward Crane | | 1960–1965 | | |
| 51 | Daniel Hayes | | 1966–1967 | | |
| 52 | Walter Sullivan | | 1968–1969 | | |
| 53 | Alfred Vellucci | | 1970–1971 | | |
| 54 | Barbara Ackermann | | 1972–1973 | | |
| 55 | Walter Sullivan | | 1974–1975 | | |
| 56 | Alfred Vellucci | | 1976–1977 | | |
| 57 | Thomas Danehy | | 1978–1979 | | |
| 58 | Francis Duehay | | 1980–1981 | | |
| 59 | Alfred Vellucci | | 1982–1983 | | |
| 60 | Leonard J. Russell | | 1984–1985 | | |
| 61 | Francis Duehay | | 1985 | | |
| 62 | Walter Sullivan | | 1986–1987 | | |
| 63 | Alfred Vellucci | | 1988–1989 | | |
| 64 | Alice Wolf | | 1990–1991 | | |
| 65 | Kenneth Reeves | | 1992–1995 | | |
| 66 | Sheila Russell | | 1996–1997 | | |
| 67 | Francis Duehay | | 1998–1999 | | |
| 68 | Anthony Galluccio | | 2000–2001 | | |
| 69 | Michael A. Sullivan | | 2002–2005 | | |
| 70 | Kenneth Reeves | | 2006–2007 | | |
| 71 | E. Denise Simmons | | 2008–2009 | | |
| 72 | David P. Maher | | 2010–2011 | | |
| 73 | Henrietta Davis | | 2012–2013 | | |
| 74 | David P. Maher | | 2014–2015 | | |
| 75 | E. Denise Simmons | | 2016–2017 | | |
| 76 | Marc C. McGovern | | 2018–2019 | | |
| 77 | Sumbul Siddiqui | | 2020–2024 | | |
| 78 | E. Denise Simmons | | 2024–present | |