Zohran Mamdani was sworn in as New York City's 112th mayor in the first minutes of the new year on Thursday, becoming the city's first Muslim mayor and pledging to use the full power of government to address affordability and support working-class residents.

Mamdani, a 34-year-old democratic socialist, took the oath of office just after midnight at the decommissioned Old City Hall subway station, one of the city's first subway stops. New York Attorney General Letitia James administered the oath at the private ceremony, with Mamdani's wife Rama Duwaji by his side.

"This is truly the honor and the privilege of a lifetime," Mamdani said in brief remarks during the ceremony.

The new mayor placed his hand on two Qurans during the oath. One belonged to his grandfather, and the other was a 200-year-old edition on loan from the New York Public Library that once belonged to Arturo Schomburg, a Black historian and key figure in the Harlem Renaissance, according to the New York Times.

A public ceremony followed later Thursday on the steps of City Hall, with U.S. Senator Bernie Sanders of Vermont administering the oath before approximately 4,000 guests. Representative Alexandria Ocasio-Cortez of New York also participated in the event.

Historic firsts and campaign promises

Mamdani is New York City's first Muslim mayor, first mayor of South Asian descent, first born in Africa, and the youngest mayor since 1892.

Born in Kampala, Uganda, to filmmaker Mira Nair and academic Mahmood Mamdani, he relocated to New York at age 7 and became a U.S. citizen in 2018. He served in the New York State Assembly representing Queens since 2020 before launching his mayoral campaign.

His campaign centered on addressing what he called the city's affordability crisis. He promised free child care, free bus service, rent freezes for approximately 1 million households in rent-stabilized apartments, and pilot city-run grocery stores.

Mamdani defeated former New York Governor Andrew Cuomo, who ran as an independent after losing the Democratic primary, and Republican Curtis Sliwa in the November election. He took 50% of the vote, nearly 10 points ahead of Cuomo, according to Reuters.

In his inaugural address at City Hall, Mamdani signaled his intention to expand government programs.

"Beginning today, we will govern expansively and audaciously," he said. "Those who insist that the era of big government is over, hear me when I say this: No longer will City Hall hesitate to use its power to improve New Yorkers' lives."

He added: "We will replace the frigidity of rugged individualism with the warmth of collectivism."

First day actions spark controversy

Mamdani wasted no time taking action, revoking all executive orders issued by former Mayor Eric Adams after his indictment on federal corruption charges in September 2024.

Among the nine revoked orders was one that had barred city agencies from boycotting or divesting from Israel, and another that had adopted the International Holocaust Remembrance Alliance's definition of antisemitism.

Israel's Foreign Ministry swiftly criticized the move.

"On his very first day as New York City Mayor Mamdani shows his true face: He scraps the IHRA definition of antisemitism and lifts restrictions on boycotting Israel," the ministry said on social media.

The New York chapter of the Council on American-Islamic Relations welcomed the decision, calling Adams' executive order an attack on free speech that would have unconstitutionally limited boycotts against Israel.

Mamdani did not revoke the city's Office to Combat Antisemitism, which Adams created in May. At a Thursday news conference, the new mayor vowed to protect Jewish New Yorkers.

"That is an issue that we take very seriously and as part of the commitment that we've made to Jewish New Yorkers: to not only protect them, but to celebrate and cherish them," Mamdani told reporters.

Housing initiatives and cabinet appointments

Mamdani signed three executive orders on his first day aimed at what he called confronting the city's housing crisis.

"Today, on the first day of this new administration, on the day where so many rent payments are due, we will not wait to deliver action. We will stand up on behalf of the tenants of this city," he said.

He appointed housing advocate Cea Weaver as director of the revitalized Mayor's Office to Protect Tenants. The office "will serve as a central coordinating body to defend tenants' rights, stand up to landlords, and ensure city agencies act swiftly on behalf of renters facing unsafe or illegal conditions," his office said.

Mamdani also established two task forces on housing. The Land Inventory Fast Track Task Force will review city-owned properties and identify sites suitable for housing development by July 1. The Streamlining Procedures to Expedite Equitable Development Task Force will identify bureaucratic barriers that slow housing construction.

His first official appointment was Mike Flynn as Commissioner of the New York City Department of Transportation.

Dean Fuleihan, the incoming deputy mayor, told the Financial Times that Mamdani will move ahead with plans to increase taxes on millionaires to pay for his campaign promises and balance New York's budget. He added that he does not expect wealthy residents to leave the city as a result.

However, New York Governor Kathy Hochul has said she opposes raising personal income taxes, though she is considering raising corporate taxes to address a potential budget shortfall amid federal cuts.

Political implications and challenges ahead

Hours after the swearing in, the National Republican Congressional Committee sought to portray Mamdani as a liability for Democrats ahead of the 2026 midterm elections.

"Every time Mamdani opens his mouth or swipes his pen, he tattoos the Democrat Party's failures onto every House Democrat facing voters in 2026," spokesperson Mike Marinella said in a statement.

Mamdani's agenda faces significant obstacles. Rent freezes are not a decision the mayor can make unilaterally. Since the 1960s, the nine-member Rent Guidelines Board, appointed by the mayor, has set rents for stabilized apartments under state law that requires consideration of landlord expenses.

Additionally, outgoing Mayor Adams recently named two new board members and reappointed two others, ensuring his appointees will constitute a majority for the foreseeable future regardless of who Mamdani appoints.

Free bus service would require cooperation from the state's Metropolitan Transportation Authority, which estimates the cost at approximately $750 million.

President Donald Trump, who once warned that Mamdani's election would be "very bad" for New Yorkers, changed his tone after hosting the mayor-elect at the White House in November.

"We had a meeting today that actually surprised me," Trump said at the time. "I expect to be helping him, not hurting him—a big help, because I want New York City to be great."

Mamdani has maintained his criticism of Trump despite the cordial meeting, telling reporters he still considers the president a "fascist."

Mamdani raised $2.6 million for his transition and inauguration from nearly 30,000 contributors, more than any other mayor on record this century. He and his wife will move from their rent-stabilized apartment in Astoria to Gracie Mansion, the official residence of New York City mayors.