Many courthouses and city clerk offices were open Sunday to handle the flood of people wanting to take advantage of the new law.
New York is the sixth and largest state to sanction gay marriage. The state's adoption of legal same-sex marriage is viewed as a pivotal moment in the national gay rights movement and was expected to galvanize supporters and opponents alike.
New York joined Connecticut, Iowa, Massachusetts, New Hampshire and Vermont, along with Washington, D.C., when it voted last month to legalize gay marriage.
Not everyone though is celebrating, however, as opponents of the law planed to protest.
The Associated Press contributed to this report.