World War II: Fiorello La Guardia, Mayor of New York City and Director of the Office of Civilian Defense, signs Administrative Order 9, creating the Civil Air Patrol.

The mayor of New York City, officially Mayor of the City of New York, is head of the executive branch of the government of New York City and the chief executive of New York City. The mayor's office administers all city services, public property, police and fire protection, most public agencies, and enforces all city and state laws within New York City.

The budget, overseen by New York City Mayor's Office of Management and Budget, is the largest municipal budget in the United States, totaling $100.7 billion in fiscal year 2021. The City employs 325,000 people, spends about $21 billion to educate more than 1.1 million students (the largest public school system in the United States), and levies $27 billion in taxes. It receives $14 billion from the state and federal governments.

The mayor's office is located in New York City Hall; it has jurisdiction over all five boroughs of New York City: Manhattan, Brooklyn, the Bronx, Staten Island and Queens. The mayor appoints numerous officials, including deputy mayors and the commissioners who head city agencies and departments. The mayor's regulations are compiled in title 43 of the New York City Rules. According to current law, the mayor is limited to two consecutive four-year terms in office but may run again after a four-year break. The limit on consecutive terms was changed from two to three on October 23, 2008, when the New York City Council voted 2922 in favor of passing the term limit extension into law. However, in 2010, a referendum reverting the limit to two terms passed overwhelmingly.The current mayor is Eric Adams, who was elected on November 2, 2021, and took office shortly after midnight on January 1, 2022.

Fiorello Henry La Guardia (; born Fiorello Enrico La Guardia, Italian pronunciation: [fjoˈrɛllo enˈriːko la ˈɡwardja]; December 11, 1882 – September 20, 1947) was an American attorney and politician who represented New York in the House of Representatives and served as the 99th Mayor of New York City from 1934 to 1945. Known for his irascible, energetic, and charismatic personality and diminutive, rotund stature, La Guardia is acclaimed as one of the greatest mayors in American history. La Guardia was frequently cross-endorsed by parties other than his own, including the Democratic Party, under New York's electoral fusion laws.

Before serving as mayor, La Guardia represented Manhattan in Congress and on the New York City Board of Aldermen. As mayor, during the Great Depression and World War II, La Guardia unified the city's transit system; expanded construction of public housing, playgrounds, parks, and airports; reorganized the New York Police Department; and implemented federal New Deal programs within the city. He pursued a long series of political reforms, curbing the power of the powerful Tammany Hall political machine and re-establishing merit-based employment and promotion within city administration.La Guardia was also a major national political figure. His support for the New Deal and relationship with President Franklin D. Roosevelt crossed party lines, brought federal funds to New York City, and cut off patronage to La Guardia's enemies. La Guardia's WNYC radio program "Talk to the People", which aired from December 1941 until December 1945, expanded his public influence beyond the borders of the city.