Vespucci, Amerigo, (Latinized form: Americus Vespucius, ) (1451–1512), the Italian navigator for whom the continents of the Western Hemisphere are named. According to letters Vespucci wrote to friends, he made four voyages to the New World—two for Spain (1497 and 1499) and two for Portugal (1501 and 1503). He claimed to have reached the coast of South America on June 16, 1497, on his first voyage. Many of Vespucci's claims are doubted by scholars, although he is generally credited with being the first European to recognize South America as a separate continent.

Vespucci's accounts of his voyages were widely publicized throughout Europe. In 1507 Martin Waldseemüller published a geography in which he suggested that the new continent be named America, after the man who, he thought, discovered it.

Vespucci was born in Florence, Italy. He was a commercial agent for the Medici family and was apparently sent by them to Spain. He became a Spanish subject in 1505 and in 1508 was appointed pilot major of Spain, an official responsible for training pilots (navigators) and collecting data concerning navigation.