The mayor of Chicago is the chief executive of city government in Chicago, Illinois, the third-largest city in the United States. The mayor is responsible for the administration and management of various city departments, submits proposals and recommendations to the Chicago City Council, is active in the enforcement of the city's ordinances, submits the city's annual budget and appoints city officers, department commissioners or directors, and members of city boards and commissions.

During sessions of the city council, the mayor serves as the presiding officer. The mayor is not allowed to vote on issues except in certain instances, most notably where the vote taken on a matter before the body results in a tie.

The office of mayor was created when Chicago became a city in 1837.

The first mayor was William B. Ogden (1837–1838). Forty-six men and two women (Jane Byrne, 1979–1983, and Lori Lightfoot, 2019–2023), have held the office. Two sets of father and son have been elected Mayor of Chicago: Carter Harrison, Sr. (1879–1887, 1893) and Carter Harrison, Jr. (1897–1905, 1911–1915), as well as Richard J. Daley (1955–1976) and Richard M. Daley (1989–2011). Carter Harrison, Jr. was the first mayor to have been born in the city.

As an interim mayor, David Duvall Orr (1987) held the office for one week, the shortest time period. Richard M. Daley was elected six times becoming Chicago's longest-serving mayor, his 22 years surpassing his father's record of 21 years.^[1]

The first Irish Catholic mayor was John Patrick Hopkins (1893–1895), and Rahm Emanuel (2011–2019) is the only Jewish American to have served as mayor.

Harold Washington (1983–1987) was the first African American mayor. Lightfoot (2019–2023) was the city's first African American woman and first LGBT mayor. Brandon Johnson (2023–present) is the third elected African American mayor, Eugene Sawyer (1987–1989) having been selected by the council after Washington died in office.

The mayor appoints the commissioner of the Chicago Fire Department, the superintendent of the Chicago Police Department and the heads of other departments,^[2] the largest of which are the Water Management Department (formed by the consolidation of the former Water Department and Sewer Department under Richard M. Daley), and the Streets & Sanitation Department. The mayor also appoints members to the boards of several special-purpose governmental bodies including City Colleges of Chicago, Chicago Park District, Chicago Public Library, Chicago Housing Authority, Chicago Transit Authority, and the Metropolitan Pier and Exposition Authority. Under Richard M. Daley, the Illinois legislature granted the mayor power to appoint the governing board and chief executive officer of the Chicago Public Schools and subordinated the district to the mayor; the district had long been an independent unit of government.

The Chicago City Clerk and City Treasurer of Chicago are elected separately, as are the 50 alderpersons who form the city council. The mayor is empowered, however, to fill vacancies in any of these 52 elected offices by appointment. In turn, the city council elects one of its own to fill a mayoral vacancy.

By charter, Chicago has a "weak-mayor" system, in which most of the power is vested in the city council. In practice, however, the mayor of Chicago has long been one of the most powerful municipal chief executives in the nation. Unlike in most other weak-mayor systems, the mayor has the power to draw up the budget. For most of the 20th century, before the decline of patronage and the mayor's office becoming officially nonpartisan in 1999, the mayor was the de facto leader of the city's Democratic Party, and had great influence over the ward organizations.^[3] Located in City Hall, "the fifth floor" is sometimes used as a metonym for the office and power of the mayor.^[4]

The mayor of Chicago is elected by popular vote every four years, on the last Tuesday in February. A run-off election, in case no candidate garners more than fifty percent of the vote, is held on the first Tuesday in April. The election is held on a non-partisan basis. Chicago is the largest city in the United States not to limit the term of service for its mayor.

In accordance with Illinois law,^[5][6] the city council elects a vice mayor who serves as interim mayor in the event of a vacancy in the office of the mayor or the inability of the mayor to serve due to illness or injury, until the city council elects one of its members acting mayor or until the mayoral term expires.^[6][7] However, if a vacancy occurs in the office of mayor with more than 28 months remaining in the mayoral term and at least 130 days before the next general municipal election, then a special election must be held to choose a new mayor to serve out the remainder of the term at that general municipal election; if a vacancy occurs with fewer than 28 months remaining in the mayoral term or fewer than 130 days before the next general municipal election, then the acting mayor serves as mayor until the mayoral term expires.

The order-of succession involving the vice mayor was made concrete following disputes that arose in the aftermath of the death in office of Richard J. Daley, and was subsequently implemented following the death in office of Harold Washington, which saw Vice Mayor David Orr become acting mayor.^[8] Prior to this, the city had vague succession laws which indicated that the president pro tempore of the City Council would succeed as mayor. This was not followed after the death of Daley, and the city council appointed Michael Bilandic acting mayor instead of having pro tempore Wilson Frost become mayor,^[9] due to City Corporation Counsel William R. Quinlan ruling that, since the city did not have a statute specifically outlining succession, the City Council would need to elect the interim mayor.^[10]

Six instances have seen the City Council appoint either an acting mayor, acting mayor pro tempore, or interim mayor.

In the absence of the mayor during meetings of the city council, the president pro tempore of the city council, who is a member of and elected by the city council, acts as presiding officer. Unlike the mayor, the president pro tempore can vote on all legislative matters. If neither the mayor nor pro tempore can preside, the vice mayor presides.^[11]

Between 1833 and 1837, Chicago was incorporated as a town and headed by town presidents. Since 1837, it has been incorporated as a city and headed by mayors.

The mayoral term in Chicago was one year from 1837 through 1863, when it was changed to two years. In 1907, it was changed again, this time to four years. Until 1861, municipal elections were held in March. In that year, legislation moved them to April. In 1869, however, election day was changed to November, and terms expiring in April of that year were changed. In 1875, election day was moved back to April by the city's vote to operate under the Cities and Villages Act of 1872.

^† Died/murdered in office.
¹ Since 1999, mayoral elections have officially been nonpartisan. A 1995 Illinois law stipulated that "candidates for mayor ... no longer would run under party labels in Chicago". However, Richard M. Daley, Rahm Emanuel, Lori Lightfoot, and Brandon Johnson are known to be Democrats.^[14]

In accordance with Illinois law, the city council elects a vice mayor who serves as interim mayor in the event of a vacancy in the office of the mayor or the inability of the mayor to serve due to illness or injury, until the city council elects one of its members acting mayor or until the mayoral term expires. The current vice mayor is Walter Burnett.

The position was created by a state law that was passed in response to the power struggle that took place over succession following Richard J. Daley's death in office.^[9][15][16]

If neither the mayor nor president pro tempore can preside over a City Council meeting, then the vice mayor presides.^[11]

The position was long considered to be largely ceremonial.^[17][18][19] However, in 2023, Mayor Brandon Johnson successfully championed a resolution that gave the office a $400,000 budget. He also had his vice mayor, Burnett, act as an official community liaison for the mayoral administration.^[20]

• Law and government of Chicago
• Timeline of Chicago history