Martinus Becanus (6 January 1563 – 24 January 1624) was a Flemish Jesuit priest, known as a theologian and controversialist.
He was born in Hilvarenbeek in the Southern Netherlands; his original surname was Schellekens. He entered the Society of Jesus on 22 March 1583, and taught Theology for twenty-two years at Würzburg, Mainz, and Vienna.
He died in Vienna, where he was the confessor to the Emperor Ferdinand II.
A first class controversialist and prolific writer Becanus is the author of some 37 books, most of them works of polemics.
- He developed the art of controversy and taught it in his book : Manuale controversiarumn huius temporis published in Wurzburg (1623), that went into more than 20 editions.
- Another book had much success: Analogia veteris et novi Testamenti.
- He supported Cardinal Bellarmine in the major allegiance oath controversy with James I of England, publishing six books in the period 1610 to 1613, one against William Tooker and another being directed at Lancelot Andrewes. At the time he was based in Mainz; he was brought into the front line of the discussion of Bellarmine's Apologia by Attileo Amalteo, the nuncio at Cologne.
Among numerous other works was his Summa Theologiae Scholasticae.