N.Y.C. Admin. Code § 2-201: § 2-201 The city of New York, territory thereof and extent of jurisdiction and powers.

All that territory within the city being all that territory contained within the boroughs of Manhattan, The Bronx, Brooklyn, Queens and Staten Island as hereafter described, shall be known as "The City of New York"; and the boundaries, jurisdictions and powers of the city are for all purposes of local administration and government hereby declared to be co-extensive with the territory above described.