Manhattan is the most densely populated and geographically smallest of the five boroughs of New York City. Coextensive with New York County, it is the smallest county by area in the U.S. state of New York and one of the smallest in the United States. Located almost entirely on Manhattan Island near the southern tip of the state, it sits centrally in the Northeast megalopolis and represents the urban core of the New York metropolitan area. The borough serves as New York City's economic and administrative center.

Before European colonization, the area was part of Lenape territory inhabited by the Munsee, Lenape, and Wappinger tribes. European settlement began with a Dutch trading post established in 1624, which became New Amsterdam in 1626. The territory came under English control in 1664 and was renamed New York after King Charles II granted the lands to his brother, the Duke of York. It served as the U.S. capital from 1785 until 1790 before becoming a borough during the consolidation of New York City in 1898.

The island is divided into Lower Manhattan, Midtown, and Upper Manhattan, bounded by the Hudson, East, and Harlem rivers. It hosts iconic landmarks such as the Statue of Liberty, Central Park, Times Square, and Grand Central Terminal. The borough is home to prominent skyscrapers including the Empire State Building, Chrysler Building, and One World Trade Center. Notable sites include the Stonewall Inn in Greenwich Village and the headquarters of the United Nations in Turtle Bay.

Manhattan is described as the cultural, financial, media, and entertainment capital of the world. It hosts three of the world's top ten most-visited tourist attractions and serves as a symbol of American ideals through the Statue of Liberty. The borough has been central to significant cultural movements, including the Harlem Renaissance in the 1920s and the modern gay-rights movement originating at the Stonewall Inn in 1969. Its fast pace and continuous urban energy define its global reputation.

The population was 1,694,251 as of 2020, living in a land area of 22.66 square miles. It produces the highest U.S. county GDP by both absolute and per capita measures and hosts Wall Street and the New York Stock Exchange. New York Penn Station is the busiest transportation hub in the Western Hemisphere. The borough contains numerous colleges, including Columbia University and New York University, and professional sports teams like the New York Knicks and New York Rangers.