Francisco Paez, a Spanish Jesuit missionary, born at Olmedo, near Valladolid, in 1564, died in Abyssinia about 1620. In 1588 he was sent from Goa with Father Antonio Montserrat to direct a mission in Abyssinia. On the voyage thither they were made prisoners by an Arab pirate and carried to Sana, the capital of Yemen, where they passed seven years. Ransomed at length by the viceroy of India, the two missionaries returned to Goa in 1596. Paez, after passing a few years at Diu and Cambay, again took ship for Abyssinia, and in 1603 reached Massowa, where he learned the native language, translated into it a compendium of the Christian doctrine, and instructed the children. The king, Za-Denghel, ordered him to appear at court with two of his pupils, and was so much impressed that ho wrote to the pope and to Philip III. of Spain for more missionaries. The Abyssinian priests stirred up an insurrection in which Za-Denghel lost his life (1604); but the next king, Susneius or Melek Seghed, was still more favorable to the Spaniard, and granted him a piece of ground for a convent. Father Paez accompanied the king on his military expeditions, and on one of these occasions discovered the sources of the Abai, the eastern upper branch of the Blue Nile, which he was the first European to visit.

Nicolas Antonio attributes to Paez a general history of Ethiopia (not published), a treatise Be Abyssinorum Erroribus, and several letters printed in the Literoe Annuoe.