Regimini militantis ecclesiae (“On the Supremacy of the Church Militant”) was the papal bull promulagated by Pope Paul III on September 27, 1540, which gave final approval to the formation of the Society of Jesus, also known as the Jesuits, but limited the number of its members to sixty, who swiftly acclaimed Ignatius as their general and solemnly pledged him absolute obedience, recognized him as "holding the place of God" in relation to them.

Ignatius Loyola had made his way to Rome in October, 1538, to have the pope approve the constitution of his new order. A congregation of cardinals reported favorably upon the constitution presented.

Its text as subsequently modified became known as the Institute, the "Constitutions" or charter of the Society of Jesus. The full text of Regimini militantis is in Reich, Documents, pp. 216-219, and a condensed version in Robinson, European History, ii. 161-165.