Zohran Mamdani, the left-leaning populist who deployed a mix of charm, social media savvy and an unyielding focus on affordability to catapult him to political stardom, was officially sworn in as mayor of New York City early Thursday, just after the New Year’s Eve ball dropped in Times Square.
The ceremony, held underground at an abandoned showpiece of a subway station by City Hall, caps Mr. Mamdani’s yearlong rise from obscure state lawmaker to international figure carrying the hopes of New Yorkers and Americans across the country who were enthralled by his journey to becoming the city’s first Muslim and first South Asian mayor.
Just after the last seconds of 2025 ticked away, Mr. Mamdani, 34, was sworn in by Letitia James, the state attorney general, as a smattering of family, friends and reporters looked on.