The Duke and Duchess of Cambridge's motorcade pulled up outside the Carlyle Hotel on the Upper East Side around 5:45 pm (local time) yesterday, and the couple smiled broadly before heading into the building.
"The Duke and Duchess of Cambridge have arrived in NYC!" the British consulate in New York tweeted, along with a picture of the beaming pair.
Kate, who is due to give birth to the couple's second baby in April, was wearing a purple maternity coat. Their first-born son George is not coming on the visit.
It is their first trip to the United States together since a brief visit to the Los Angeles region in 2011.
William is scheduled to meet US President Barack Obama in the White House today for talks about illegal wildlife trading, an issue close to the prince's heart.