As of January 1, 2013, the Office of Mayor of the City of Baltimore has changed hands 59, times with 49 different individuals assuming office. James Calhoun was first elected in 1794 under the old Town government, and continued as the new first mayor under the new City charter in 1796-97, when the City was incorporated as the "City of Baltimore" ("Mayor and City Council of Baltimore") under the authority of the General Assembly of Maryland. Calhoun continued to serve until 1804.
Serving as the "county seat" of surrounding Baltimore County since 1767, the City was separated from the county by the provisions of the adoption of the new second Maryland Constitution of 1851 and became an independent city with the same status as the other 22 (later 23) counties of Maryland. Then the county seat for Baltimore County was moved after an election/referendum to Towsontown (later Towson, Maryland) with the building there of its first courthouse in 1854.
Six individuals are credited with multiple, non-consecutive returns to the office after completing an initial term, and are counted as separate mayoralties. These are: Edward Johnson (twice), John Montgomery, Ferdinand C. Latrobe (elected four times), Howard W. Jackson, William F. Broening, and Theodore R. McKeldin.
Originally elected for a term of only two years under the original first City Charter, now traditionally, the Baltimore City Charter limits a mayoral term to four years since the revisions of 1920 (who can be reelected without term limits). However, the 2015 election will be postponed to 2016 in order to better align with national elections.