It is the first time the company has created a software base that is not on the US West Coast.
A reports also suggest the
social network has bought Gowalla - a location-based "check-in" service.
Facebook's chief operating officer, Sheryl Sandberg, announced the New York expansion plan at a press conference attended by the city's Mayor, Michael Bloomberg, and other officials.
"We are trying to grow at a clip that will allow us to get the very best people and integrate them," she said.
"We will be adding thousands of employees in the next year."
The new office will be headed up by Serkan Piantino. He previously led the engineering team behind Facebook's News Feed and helped develop its Timeline feature.
Ms Sandberg did not specify how many of the "thousands" of promised posts would be created in New York.
Reports suggest the firm has also taken over Gowalla.
Texas-based Gowalla is a two-year-old social network based around the idea of allowing users to "check-in" to locations and share pictures from their visits.
Members used to receive virtual "items" at certain check-in points. However, the company struggled against a larger competitor, Foursquare. In September it refocused its efforts on becoming a travel service, offering "social guides" to 60 cities, including London, Paris and Chicago, based on its members' postings.
At the end of last week CNN reported that Facebook had bought the firm for an undisclosed sum and would move Gowalla's development team onto its Timeline feature.
Timeline turns users' Facebook profile pages into a digital scrapbooks, making it easier for users to view each others' life histories. The feature was announced in September, but has yet to be rolled out to many of the site's members.
Facebook keep it up, you are doing a nice job .
