He will replace Eric Adams, the current mayor, whose term ends on December 31, 2025.

Uganda-born Mamdani, 34, a Democratic Socialist and former New York State assemblyman, won the mayoral election on November 4, 2025.

His inauguration will be a two-part event, including a midnight ceremony where New York Attorney General Letitia James will administer the oath, followed by a public ceremony later in the day.

According to media reports, Mamdani plans to take his oath on the holy Quran.

Mamdani campaigned on a platform focused on affordability, which included plans for fare-free buses, universal childcare, and a rent freeze on regulated apartments.

Senator Bernie Sanders, also a democratic socialist, will swear in Mamdani at the public ceremony to be attended by thousands of New Yorkers.

Sanders praised Mamdani for running an “inspirational” campaign and being a “visionary” leader when he endorsed him in June.

Mamdani defeated former New York Governor Andrew Cuomo last month with 50.8 per cent of the vote compared to Cuomo’s 41.3 per cent.

More than 1.1 million New Yorkers voted for Mamdani, who became the first mayoral candidate to win more than 1 million votes across the Big Apple since 1969.