The Mayor is the Chief Executive Officer of the City. He is also a Magistrate.
The Mayor has the power to appoint and remove the commissioners of more than 40 city agencies and members of City boards and commissions. The Mayor is responsible for preparing and administering the City's annual Expense and Capital Budgets and financial plan. He is responsible for managing the City's relations with federal, state and local governing entities. The Mayor has the power to veto local laws enacted by the City Council, but such a veto may be overridden by a two-thirds vote of the Council. Pursuant to State law, the Mayor appoints Criminal Court Judges, Family Court Judges and Interim Civil Court Judges. The Mayor has powers and responsibilities relating to land use and City contracts and collaborates with city, state and federal agencies responsible for the City's economic development and infrastructure. The Mayor maintains a liaison with governmental bodies dealing with pensions, public finance, procurement and franchises and concessions. The Mayor has all residual powers of the City government not otherwise delegated by law to some other public official or body. In the event of the resignation, death or removal of a Mayor, the Public Advocate serves as Acting Mayor until a special election or general election is held, depending on when the vacancy in the Office arises.

The Mayor sits ex officio on the boards of the 33 City-owned cultural institutions that are part of the Cultural Institutions Group as well as the Brooklyn Public Library, Center for Arts Education, Jazz at Lincoln Center, Museum of Arts and Design, Museum of Modern Art, New York Public Library and Queens Borough Public Library.