Martin Behaim (October 6, 1459 – July 29, 1507), or Behem, was a navigator and geographer of great pretensions.

Behaim was born at Nuremberg, according to one tradition, about 1436; according to Ghiilany, as late as 1459. He was drawn to Portugal by participation in Flanders trade, and acquired a scientific reputation at the court of John II. As a pupil, real or supposed, of the astronomer Regiomontanus (i.e. Johann Müller of Königsberg in Franconia) he became (c. 1480) a member of a council appointed by King John for the furtherance of navigation. His alleged introduction of the cross-staff into Portugal (an invention described by the Spanish Jew, Levi ben Gerson, in the ~4th century) is a matter of controversy; his improvements in the astrolabe were perhaps limited to the introduction of handy brass instruments in place of cumbrous wooden ones; it seems likely that he helped to prepare better navigation tables than had yet been known in the Peninsula. In 1484-1485 he claimed to have accompanied Diogo Cão in his second expedition to West Africa, really undertaken in 1485-86, reaching Cabo Negro in 15°40 S. and Cabo Ledo still farther on. It is now disputed whether Behaims pretensions here deserve any belief; and it is suggested that instead of sharing in this great voyage of discovery, the Nuremberger only sailed to the nearer coasts of Guinea, perhaps as far as the Bight of Benin, and possibly with José Visinho the [...]