United States v. Wong Kim Ark, 169 U.S. 649 (1898), is a United States Supreme Court case in which the Court ruled that practically everyone born in the United States is a U.S. citizen. This decision established an important precedent in its interpretation of the Citizenship Clause of the Fourteenth Amendment to the Constitution.

Wong Kim Ark, who was born in San Francisco to Chinese parents around 1871, had been denied re-entry to the United States after a trip abroad, under a law restricting Chinese immigration and prohibiting immigrants from China from becoming naturalized U.S. citizens. He challenged the government's refusal to recognize his citizenship, and the Supreme Court ruled in his favor, holding that the citizenship language in the Fourteenth Amendment encompassed essentially everyone born in the U.S.—even the U.S.-born children of foreigners—and could not be limited in its effect by an act of Congress. (more...)