Formerly known as the Freedom Tower, One World Trade Center is the primary replacement building of the original World Trade Center twin towers in New York City's Lower Manhattan that were destroyed during the terrorist attacks of September 11, 2001. The 104-story super-tall skyscraper stands on the northwest corner of the 16-acre (6.5 ha) World Trade Center site, occupying the former location of the original 6 World Trade Center. The tower's main steel structure was completed August 30, 2012. On May 10, 2013, the final component of the skyscraper's spire was installed, making One World Trade Center the tallest building in the Western Hemisphere at the time and the fourth-tallest skyscraper in the world by pinnacle height. Its spire reaches a symbolic height of 1,776 feet (541 m) in reference to the year of the United States Declaration of Independence.

In addition to the One World Trade Center , three other high-rise office buildings and the National September 11 Memorial & Museum will be built to form the new World Trade Center complex where the Twin Towers once stood.

Designed by renowned architect David Childs, of Skidmore, Owings and Merrill, LLP, One World Trade Center incorporates many new architectural and environmental standards for both safety and sustainability. The building was jointly developed by The Port Authority of New York and New Jersey and The Durst Organization. It features 3 million square feet of office space on 71 office floors, a grand public lobby, and an observation deck.