Japan–United States relations () refers to international relations between Japan and the United States. Relations began in the late 18th and early 19th century, with the diplomatic but force-backed missions of U.S. ship captains James Glynn and Matthew C. Perry to the Tokugawa shogunate. The countries maintained relatively cordial relations after that. Potential disputes were resolved. Japan acknowledged American control of Hawaii and the Philippines and the United States reciprocated regarding Korea. Disagreements about Japanese immigration to the U.S. were resolved in 1907. The two were allies against Germany in World War I.