The Mayor of the City of Saint John is the head of the elected municipal council of Saint John, New Brunswick, Canada. Saint John Common Council consists of a mayor (chair) and 10 councillors. The city has a ward system with four of roughly equal population. This municipal arrangement was first adopted in the 2008 municipal election after a plebiscite held October 9, 2007. The mayor is directly elected along with two councillors that run at large. Since 2021, the deputy mayor has been chosen by Common Council after each election, having previously been the councillor at large who gained a plurality of votes. The current deputy mayor is John MacKenzie. Each ward elects two councillor.

Since the incorporation of Saint John in 1785, the mayor has served as the chief representative of the city. Officeholders were first appointed by the Governor of New Brunswick, under an order in council. By the end of the end of the nineteenth century, the mayor was elected by the alderman of Common Council. In 1854, the office was directly elected by Saint John residents. As head of the largest city in New Brunswick, many mayors have served as elected officials at the federal and provincial level both before and after their tenure.

Since 1785, 67 individuals have held the office of mayor. Notably, Samuel Davis, 1977-1980, served as the first elected Jewish Mayor of Saint John. In 1983 Elsie Wayne was elected the first woman mayor. She served until 1993. While serving only two years, Thomas J. Higgins was the first Catholic Mayor of Saint John. The former, Don Darling, was elected May 9, 2016. Donna Reardon, incumbent, was elected May 25, 2021.

List of Mayors

Appointed by Governor-In-Council

1. Gabriel G. Ludlow, 1785-1795
2. William Campbell, 1795-1816
3. John Robinson, 1816-1828 (Died In Office)
4. William Black, 1828-1829
5. Lauchlan Donaldson, 1829-1832
6. William Black, 1832-1833
7. John M. Wilmot, 1833-1834
8. Benjamin L. Peters, 1834-1835
9. William H. Street, 1835-1836
10. John Robertson, 1836-1837
11. Robert F. Hazen, 1837-1840
12. William Black, 1840-1843
13. Lauchlan Donaldson, 1843-1847
14. John R. Partelow, 1847-1848
15. William H. Street, 1848-1849
16. Robert D. Wilmot, 1849-1850
17. Henry Chubb, 1850-1851

Elected indirectly by Common Council

1. Thomas Harding, 1851-1852
2. William O. Smith, 1852-1853
3. James Olive, 1853-1854

Elected directly by residents

1. James Olive, 1854-1855
2. William O. Smith, 1855-1859
3. Thomas Mcavity, 1859-1863
4. Isaac Woodward, 1863-1866
5. Aaron Alward, 1866-1870
6. Thomas M. Reed, 1870-1874
7. A. Chipman Smith, 1874-1877
8. Sylvester Z. Earle, 1877-1879
9. Charles R. Ray, 1879-1881
10. Simeon Jones, 1881-1884
11. J. Mcgregor Grant, 1884-1885
12. J.S. Boies Deveber, 1885-1887
13. Henry J. Thorne, 1887-1889
14. George A. Barker, 1889 (Died In Office)
15. I. Allen Jack, July 7-August 9, 1889 (As Recorder Under City Charter)
16. W. Albert Lockhart, 1889-1891
17. Thomas W. Peters, 1891-1894
18. George Robertson, 1894-1898
19. Edward Sears, 1898-1900
20. John Waterhouse Daniel, 1900-1902
21. Walter W. White, 1902-1906
22. Edward Sears, 1906-1908
23. Thomas H. Bullock, 1908-1910
24. James H. Frink, 1910-1916
25. Robert T. Hayes, 1916-1920
26. E. Allen Schofield, 1920-1922
27. Harry R. Mclellan, 1922
28. G. Frederick Fisher, 1922-1924
29. Frank L. Potts, 1924-1926 (Died In Office)
30. Walter W. White, 1926-1932
31. James W. Brittain, 1932-1936
32. D. Laurence Maclaren, 1936-1940
33. Charles R. Wasson, 1940-1944
34. James D. McKenna, 1944-1948
35. Ernest W. Patterson, 1948-1950
36. George E. Howard, 1950-1952
37. Ernest W. Patterson, 1952-1954
38. Gilbert B. Peat, 1954-1956
39. William W. Macaulay, 1956-1958
40. D. Laurence Maclaren, 1958-1960 (Died In Office)
41. James A. Whitebone, 1960
42. Eric L. Teed, 1960-1964
43. Stephen H. Weyman, 1964-1966
44. Arthur L. Gould, 1966
45. Arthur L. Gould, January–June 1967
46. Joseph A. Macdougall, 1967-1969
47. H. Avard Loomer, 1969 (Died In Office)
48. James E. Calvin, 1969-1971
49. Bob Lockhart, 1971-1974
50. Edis A. Flewwelling, 1974-1977
51. Samuel Davis, 1977-1980
52. Bob Lockhart, 1980-1983
53. Elsie Wayne, 1983-1993
54. Thomas J. Higgins, 1994-1995
55. Shirley McAlary, 1995-2004
56. Norman McFarlane, 2004-2008
57. Ivan Court, 2008-2012
58. Mel Norton, 2012-2016
59. Don Darling, 2016-2021
60. Donna Reardon, 2021-Present