The Peace Palace (Dutch: Vredespaleis [ˈvreːdəspaːˌlɛis]; The Hague dialect: Freidespalès [ˈfʁeidəspaːˌlɛːs]) is an international law administrative building in The Hague, Netherlands. It houses the International Court of Justice (which is the principal judicial body of the United Nations), the Permanent Court of Arbitration (PCA), The Hague Academy of International Law and the Peace Palace Library.

The palace officially opened on 28 August 1913; it was built to provide a courthouse for the Permanent Court of Arbitration, a court created to end war by the Hague Convention of 1899. In addition to its function as the headquarters of the Permanent Court of Arbitration since 1913 and of the International Court of Justice since 1946, the palace continues to serve as the Courts' main hearing facilities and hosts dozen of hearings each year.

Following the creation of the Permanent Court of Arbitration in 1899, its Founding States decided to build a dedicated courthouse to support the Court's mission and encourage States to resolve their disputes peacefully: the Peace Palace.

The idea of the palace started from a discussion in 1900 between the Russian diplomat Friedrich Martens and American diplomat White over providing a home for the Permanent Court of Arbitration (PCA). Andrew Dickson White, whose efforts were instrumental in creating the court, secured from Scottish-American steel magnate Andrew Carnegie US$1.5 million ($50,000,000, adjusted for inflation) to build the Peace Palace.

White contacted Andrew Carnegie. Carnegie had reservations, and at first was only interested in donating money for the establishment of a library of international law. White, however, was able to convince Carnegie, and in 1903 Carnegie agreed to donate the US$1.5 million ($50,000,000, adjusted for inflation) needed to house the court as well as to endow it with a library of international law. White described his idea to Carnegie:

"A temple of peace where the doors are open, in contrast to the Janus-temple, in times of peace and closed in cases of war [...] as a worthy testimony of the people that, after many long centuries finally a court that has thrown open its doors for the peaceful settlement of differences between peoples".

Were such a fabric to be created, men would make pilgrimages from all parts of the civilized world to see it. It would become a sort of holy place, prized and revered by thinking men throughout the world, and to which, in any danger of war between any two countries, the minds of men would turn naturally and normally. The main difficulty now is that the people of the various nations do not really know what was done for them by the Conference; but such a building would make them know it. It would be an "outward and visible sign" of the Court, which would make its actual, tangible existence known to the ends of the earth"

In September 1903, the Minister of Foreign Affairs of the Netherlands established an Advisory and Preparatory Commission to launch an open competition for the design of the courthouse. The Commission drafted a program of requirements for the architectural competition and visited prominent courthouses to determine the building's needs.