The Flatiron District is a neighborhood in the New York City borough of Manhattan, named after the Flatiron Building at 23rd Street, Broadway and Fifth Avenue.Generally the Flatiron District is bounded by 14th Street, Union Square and Greenwich Village to the south; the Avenue of the Americas (Sixth Avenue) and Chelsea to the west; 23rd Street and Madison Square (or NoMad) to the north; and Park Avenue and Gramercy Park to the east.

Broadway cuts through the middle of the district, and Madison Avenue begins at 23rd Street and runs north. At the north (uptown) end of the district is Madison Square Park, which was completely renovated in 2001. The Flatiron District encompasses within its boundaries the Ladies' Mile Historic District and the birthplace of Theodore Roosevelt, a National Historic Site. The Flatiron District was also the birthplace of Silicon Alley, a metonym for New York's high technology sector, which has since spread beyond the area.