Martin Delrio, Flemish theologian and author (b. 1551)
Martin Anton Delrio SJ (Latin: Martinus Antonius Delrio; Spanish: Martín Antonio del Río; French: Martin-Antoine del Rio; 17 May 1551 – 19 October 1608) was a Jesuit theologian, born in the Low Countries but of Spanish descent. He studied at numerous institutions, receiving a master's degree in law from Salamanca in 1574. After a period of political service in the Spanish Netherlands, he became a Jesuit in 1580.

He studied or taught at Jesuit colleges across Catholic Europe, including Bordeaux, Douai, Graz, Mainz, Leuven, and Salamanca. He was the friend of the Flemish humanist Justus Lipsius, a relative of Michel de Montaigne, and an enemy of the Protestant scholar Joseph Scaliger. He was the author of a large number of books, including classical commentaries and works of biblical exegesis. He remains, however, best known for his six-volume Magical Investigations (1599–1600), a work on magic, superstition, and witchcraft.