João Fernandes (John, Joam) was a Portuguese traveller of the 15th century. He was perhaps the earliest of modern explorers in the upland of West Africa, and a pioneer of the European slave- and gold-trade of Guinea.

We first hear of him (before 1445) as a captive of the Barbary Moors in the western Mediterranean; while among these he acquired a knowledge of Arabic, and probably conceived the design of exploration in the interior of the continent whose coasts the Portuguese were now unveiling. In 1445 he volunteered to stay in Guinea and gather what information he could for Prince Henry the Navigator; with this object he accompanied Antão Gonçalves to the "River of Gold" (Rio d'Ouro, Rio de Oro) in 23 40' N., where he landed and went inland with some native shepherds. He stayed seven months in the country, which lay just within Moslem Africa, slightly north of Pagan Negroland (W. Sudan); he was taken off again by Gonçalves at a point farther down the coast, near the "Cape of Ransom" (Cape Mirik ), in 190 22' 14"; and his account of his experiences proved of great interest and value, not only as to the natural features, climate, fauna and flora of the south-western Sahara, but also as to the racial affinities, language, script, religion, nomad habits, and trade of its inhabitants. These people though Mahommedans, maintaining a certain trade in slaves, gold, &c., with the Barbary coast (especially with Tunis), and classed as "Arabs," "Berbers," and "Tawny Moors" did not then write or speak Arabic. In 1446 and 1447 John Fernandez accompanied other expeditions to the Rio d'Ouro and other parts of West Africa in the service of Prince Henry. He was personally known to Gomes Eannes de Azurara, the historian of this early period of Portuguese expansion; and from Azurara's language it is clear that Fernandez' revelation of unknown lands and races was fully appreciated at home. See Azurara, Chronica de . . . Guine, chs. xxix., xxxii., xxxiv., xxxv., lxxvii., lxxxiii., xc., xci., xciii.