By a wide margin, the U.S. has more immigrants than any other country in the world. As of 2015, the United Nations estimates that 46.6 million people living in the United States were not born there. This means that about one-in-five international migrants (19%) live in the U.S. The U.S. immigrant population is nearly four times that of the world’s next largest immigrant destination – Germany, with about 12 million immigrants.
(The UN’s figure of 46.6 million includes Puerto Ricans and others born in U.S. territories; they are not counted as immigrants by the U.S. Census Bureau or in most Pew Research Center publications. People born in Puerto Rico and U.S. territories are U.S. citizens at birth. Several other countries such as France, the United Kingdom and China also have territories and special administrative regions which the UN treats as distinct origins and destinations of international migrants.)