The Ugandan-born Mamdani, a Democrat, beat former New York Governor Andrew Cuomo, running as an independent, to become the youngest person in over a century to lead the largest city in the US. BBC reported.
A self-described democratic socialist, he made affordability the central message of his campaign, pledging to expand social programmes paid for by new taxes on high earners and corporations.
Mamdani was a relatively unknown member of New York State Assembly until his campaign gained online momentum a few months ago, propelling him to victory in the Democratic primary contest over the summer.
