John Bassett Moore (December 3, 1860 – November 12, 1947) was an American lawyer and authority on international law.

[5] After the close of the war with Spain was secretary and council to the American Peace Commission at Paris.

Subsequently, Moore represented the government as agent before the United States and Dominican Arbitration Tribunal (1904), as delegate to the Fourth International American Conference at Buenos Aires and special plenipotentiary to the Chilean centenary (both 1910), and as delegate to the International Commission of Jurists at Rio de Janeiro (1912).

He was also a strong believer in the principle of separation of powers under the United States Constitution, asserting in 1921, "There can hardly be room for doubt that the framers of the constitution, when they vested in Congress the power to declare war, never imagined that they were leaving it to the executive to use the military and naval forces of the United States all over the world for the purpose of actually coercing other nations, occupying their territory, and killing their soldiers and citizens, all according to his own notions of the fitness of things, as long as he refrained from calling his action war or persisted in calling it peace.

"[8] Moore was honored on a U.S. definitive postage stamp issued December 3, 1966, the five-dollar value of the Prominent Americans series.

[4] Moore died at his home in New York City on November 12, 1947, and was buried in Woodlawn Cemetery.