multidisciplinary contemporary arts organization based in New York (New York City), N.Y., U.S. The nonprofit foundation fosters art projects and houses art installations at various locations in the United States. Its name is derived from the Greek word meaning “through” and indicates the organization's goal to serve as a vehicle that enables the production and display of large-scale works.

The German art dealer Heiner Friedrich and his wife, Philippa de Menil (daughter of the noted philanthropist Dominique de Menil), founded the Dia Art Foundation in 1974. The foundation initially focused on commissioning works by a select group of contemporary artists—notably, minimalists and conceptual artists. Supporting projects that did not fit into the traditional museum model, the Dia commissioned large-scale, often site-specific works such as Walter De Maria's The Lightning Field (1977), a series of lightning rods arranged in a grid formation in the southwestern New Mexico desert. Plagued by financial problems in the early 1980s, the foundation was reorganized and renamed in 1985.

Since 2003 Dia has kept its public collection in Beacon, N.Y., in the Hudson Valley. The museum, known as Dia:Beacon, houses the centre's major collection, which focuses on works from the 1960s to the present. The space is on the banks of the Hudson River, and the galleries are named after Louise and Leonard Riggio, major benefactors to the centre. The expansive building was originally constructed in 1929 as a factory for Nabisco. The structure, a model of early 20th-century industrial architecture, is an ideal space to showcase contemporary art because of the numerous skylights and the use of steel, glass, and concrete in the building design. The building features 250,000 square feet (23,200 square metres) of exhibition space, and many of the galleries were created in collaboration with the artists whose works are housed in them. Major artists on display include Andy Warhol (Warhol, Andy), Richard Serra (Serra, Richard), Donald Judd (Judd, Donald), and Dan Flavin (Flavin, Dan).

In 2007 Dia began a short-term collaboration with New York City's Hispanic Society of America to showcase contemporary art while the foundation prepares a permanent home in New York City.