Covilham, Or Covilhao, Joao Peres Da, a Portuguese navigator, born at Covilhao about the middle of the 15th century, died in Abyssinia toward the middle of the 16th. He passed part of his early life in the Castilian service, and afterward became a man-at-arms in the household of Alfonso V. and John II. of Portugal, participating in several campaigns. He was employed in a mission to the Barbary states, where he acquired a knowledge of the Arabic language, which qualified him for a more important expedition to Abyssinia, said to have been destined for the discovery of the kingdom of the mysterious Prester John, and also for commercial purposes. With Affonso de Paiva he left Lisbon May 7, 1487, reaching Abyssinia by the way of Cairo and Aden.. After the death of his companion he visited the principal towns of the coast of Malabar, and returned to Abyssinia in 1490, presented to the ruler the letters addressed by John II. to the legendary Prester John, and was detained at his court, marrying a wealthy Abyssinian woman, and leading a life of ease, though regretting his involuntary exile.

The principal result of his explorations was its paving the way for Vasco da Gama's discovery of the route to India round the cape of Good Hope, the itinerary of Covilham being of considerable use to Da Gama. The fullest information about him is contained in the Verdadeira informagao do Preste-Jodo das Indias, etc, by Francisco Alvarez, chaplain of the Portuguese embassy who visited Covilham in Abyssinia (Lisbon, 1540).