Zohran Mamdani officially became New York City’s 112th mayor just after midnight on New Year’s Day, taking the oath of office in a private ceremony held inside the long-closed Old City Hall subway station beneath Manhattan.

The 34-year-old former state lawmaker was sworn in by New York Attorney General Letitia James as the clock struck midnight, marking the formal transfer of power required under New York law, which mandates that mayoral terms begin on Jan. 1 following an election.

“This is truly the honor and the privilege of a lifetime,” Mamdani said briefly after taking the oath.

The rarely accessed subway station, decommissioned in the mid-20th century, was selected to symbolize Mamdani’s emphasis on public infrastructure and working-class New Yorkers. His transition team said the location reflects “the importance of public transit to the vitality, health, and legacy of the city.”

Mamdani, a democratic socialist who represented the Queens neighborhood of Astoria in the State Assembly, is New York City’s first Muslim mayor and the first of South Asian descent. He built his campaign around affordability, pledging to freeze rents, expand free bus service, and broaden access to childcare, proposals that helped drive a record turnout of more than 2 million voters.

He captured roughly 50% of the vote, finishing nearly 10 points ahead of former Governor Andrew Cuomo, who ran as an independent, and well ahead of Republican candidate Curtis Sliwa.

Attorney General James, one of Mamdani’s earliest high-profile supporters, administered the oath. Political observers said her role underscored Mamdani’s alignment with progressive Democratic leaders and signaled his intention to govern independently of the White House. Syracuse University political science professor Grant Reeher said the choice “underscored Mamdani’s intent to chart his own course.”

Born in Uganda, Mamdani has been outspoken on issues including immigration and economic inequality and has drawn inspiration from former Mayor Bill de Blasio, whom he has described as the best mayor of his lifetime. De Blasio also began his first term with a private swearing-in by the state attorney general before holding a public ceremony later that day.

Mamdani is scheduled to take a public oath Thursday afternoon on the steps of City Hall, administered by U.S. Senator Bernie Sanders of Vermont, whom Mamdani has long cited as a political inspiration. U.S. Representative Alexandria Ocasio-Cortez is also expected to participate.

The public celebration, branded by organizers as the “Inauguration of a New Era,” will include speeches, music, and performances for thousands of invited guests in City Hall Plaza, with free viewing areas and a livestream available along Broadway.

Campaign finance disclosures show Mamdani raised about $2.6 million for inauguration and transition events from nearly 30,000 contributors, the highest total for a New York mayoral inauguration this century.

After taking office, Mamdani is expected to move from his rent-stabilized apartment in Astoria to Gracie Mansion on Manhattan’s Upper East Side, the official residence of New York City mayors.