Martin Henry Kennelly was an American politician and businessman. He served as the 47th Mayor of Chicago in Chicago, Illinois from April 15, 1947 until April 20, 1955. Kennelly was a member of the Democratic Party. According to biographer Peter O'Malley, he was chosen as mayor by a scandal-burdened Democratic machine that needed a reformer on top of the ticket. Kennelly was a wealthy businessman and civic leader, active in Irish and Catholic circles. As a long-time opponent of machine politics he accepted the nomination on condition the machine would not pressure him for patronage and that he did not have to play a leadership role in the party. This gave him a non-partisan image that satisfied the reform element. As mayor he avoided partisanship and concentrated on building infrastructure and upgrading the city bureaucracy. He worked to extend civil service; he reorganized inefficient departments. The city took ownership of the mass transit system. He obtained federal aid for slum clearance and public housing projects and for new expressways construction. At his death, Mayor Richard J. Daley, the party leader who defeated Kennelly in a bitter primary battle in 1955, called him, "a great Chicagoan who loved his city" and ordered City hall flags placed at half-mast.

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.