Previously children as young as 14 could get married with parental permission and consent of a judge in the state that stretches from New York City north to Canada and west to the Great Lakes.
The new law, signed by the governor of New York Andrew Cuomo, still allows for marriage at the age of 17 with parental and judicial permission.
In the United States, some 170,000 children were wed between 2000 and 2010 in 38 of the 50 states where data was available, according to anti-child marriage group Unchained at Last.