1 Hanover Square

One Hanover (formerly known as India House, Hanover Bank Building, and New York Cotton Exchange Building) is a commercial building at 1 Hanover Square, on the southwestern edge of the square, in the Financial District of Lower Manhattan in New York City. It was the site of the United States' first cotton futures exchange, the New York Cotton Exchange.

One Hanover is composed of four originally separate structures. The main structure is a three-story brownstone building designed in the Italian Renaissance style and completed in 1854. The brownstone contains the building's main entrance facing Hanover Square. Adjoining the brownstone are three brick structures at 60–64 Stone Street, which date to 1836 and were built as commercial stores. The brick buildings are four stories tall but are the same height as the brownstone. Inside are maritime-themed spaces that are used by Harry's Bar, Ulysses Folk House, and the India House club.

The brownstone initially served as the headquarters of the Hanover Bank, while other commercial tenants occupied the brick buildings. The New York Cotton Exchange, founded in 1870, occupied the building from 1872 to 1885. The building subsequently served as the headquarters of W.R. Grace and Company until the early 1910s. In 1914, the structures were purchased by the India House, a private club for gentlemen involved in foreign commerce, which continues to occupy the building. The building is now owned by SomeraRoad Inc., and houses their New York City HQ. Over the years, various architects have made renovations to One Hanover Square, with the three Stone Street stores being gradually combined with the brownstone structure between the 1870s and 1910s. Restaurants have also been housed in various portions of One Hanover Square throughout its history.

One Hanover's design, especially in regard to its later use as the India House clubhouse, has received critical acclaim. The building was designated a city landmark by the New York City Landmarks Preservation Commission (LPC) in 1965, was added to the National Register of Historic Places (NRHP) in 1972, and became a National Historic Landmark in 1977. It is a contributing property to the Stone Street Historic District, which was designated by the LPC in 1996 and by the NRHP in 1999. 1 Hanover Square has been depicted in works of popular culture, including the 2001 film Kate & Leopold.