Arcadia (, Arkadía) is one of the regional units of Greece. It is part of the administrative region of Peloponnese. It is situated in the central and eastern part of the Peloponnese peninsula. It takes its name from the mythological character Arcas. In Greek mythology, it was the home of the god Pan. In European Renaissance arts, Arcadia was celebrated as an unspoiled, harmonious wilderness.

The First Washington Conference, also known as the Arcadia Conference (ARCADIA was the code name used for the conference), was held in Washington, from December 22, 1941 to January 14, 1942.