Boston has five mayor in one calendar year.

Martin Brimmer finishes his term of office on January 6, 1845. But because with no candidate receiving sufficient votes in previous December election, William Parker, chairman of the Board of Alderman, serves as acting mayor until Thomas Davis takes office on February 27, 1845. Davis proceeds to die in office, leading to Benjamin Leavitt serving as acting mayor from November 22, 1845, until the next mayor, Josiah Quincy Jr., assumes office on December 11, 1845.