Reformed orthodoxy or Calvinist orthodoxy was an era in the history of Calvinism in the 16th to 18th centuries. Calvinist orthodoxy was paralleled by similar eras in Lutheranism and tridentine Roman Catholicism after the Counter-Reformation. Calvinist scholasticism or Reformed scholasticism was a theological method that gradually developed during the era of Calvinist Orthodoxy.

Theologians used the neo-Aristotelian form of presentation, already popular in academia, in their writings and lectures. They defined the Reformed faith and defended it against the polemics of opposing parties. While the Reformed often used "scholastic" as a term of derision for their Roman Catholic opponents and the content of their theology, most Reformed theologians during this period can properly be called scholastics with respect to the method of theology, though they also used other methods. J. V. Fesko describes scholasticism in this sense as "a method of doing theology that sets out to achieve theological precision through the exegesis of Scripture, an examination of how doctrine has been historically defined throughout church history, and how doctrine is expounded in contemporary debate."

In the past, scholars described the theology of Protestant scholastics following John Calvin as more rationalistic and philosophical than the more exegetical biblical theology of John Calvin and other early Reformers. This is commonly described as the "Calvin against the Calvinists" paradigm. Beginning in the 1980s, Richard Muller and other scholars in the field provided extensive evidence showing both that the early Reformers were deeply influenced by scholasticism and that later Reformed scholasticism was deeply exegetical, using the scholastic method to organize and explicate exegetical theology.

Medieval schools of theology used methods of instruction known as lectio-meditatio-quaestio and disputationes. In the first method, teachers would first read an authoritative text with some commentary (lectio), allow students to consider the text silently (meditatio), and finally the students would ask questions of the teacher to get at the meaning (quaestio).

Scholasticism was used by Protestant theologians primarily from 1560 to 1790, which is known as the period of orthodoxy because of the importance of adherence to and defense of the newly written Reformed confessions of faith for these theologians.

John Calvin, unlike other early reformers like Martin Luther, was not formally trained in theology; while Calvin was trained in law, Luther was trained in both law and theology. Like many early reformers, however, he was influenced by Renaissance humanism, which led to an interest in the original meaning of biblical and patristic texts and criticism of medieval scholastics for straying from this meaning in favor of philosophical distinctions. Analysis of his work, however, shows that he found himself using some of the same distinctions employed by the scholastics, and some of the criticisms he made of scholastic theology may have actually been based on his own misunderstanding. It is clear, however, that Calvin's use of scholastic theology is different in that, while medieval scholastic theology was solely employed by professional theologians in the schools, rather than by ordinary clergy in preaching, Calvin saw theological teaching as one of the primary objectives of the church and intended his theological works to be used by both preachers and common people. Many of his criticisms of purely speculative scholastic theology may be seen as a consequence of his desire to make theology accessible and useful for the church rather than solely for professional theologians in the schools.

Though scholasticism can already be seen in early Reformed theologians, especially Vermigli and to some degree Calvin, it became much more prevalent during the third and fourth generations of Reformed theologians as a tool to institutionalize the faith by codifying it in confessions and works of systematic theology, as well as to combat the growing sophistication of counter-Reformation polemicists. Reformed confessions of faith such as the Heidelberg Catechism of 1563 (commissioned by Elector Frederick III of the Palatinate), the Belgic Confession of 1561, and the French Gallican Confession of 1559 served as boundary markers for the new faith and as starting places for theological development. The formation of the Genevan Academy in 1559 also enabled Reformed theologians to receive extensive academic training and participate in the wider academic theological discourse. It also served as a model for other Reformed institutions of higher learning throughout Europe. Counter-Reformation attacks from Roman Catholic writers such as Jesuit Cardinal Robert Bellarmine were written in the tradition of scholasticism and needed to be answered in kind. Reformed theologians such as Heidelberg professors Zacharias Ursinus and Girolamo Zanchi adopted the tools of scholastic theology such as the quaestio method to rigorously exposit the Reformed confessions.

The early 17th-century Arminian controversy, in which a group known as the Remonstrants argued that predestination to salvation is based on God foreseeing a person's faith, brought about the Synod of Dort, which defined the Reformed doctrine on this matter in greater detail. The 1594 treatise by Huguenot theologian Franciscus Junius On True Theology was the first Protestant work to distinguish archetypal theology (God's knowledge of himself) and ectypal theology (our knowledge of God based on his condescending revelation to us). This distinction, which has its roots in the medieval Scotist distinction between theology in itself (theologia in se) and our theology (theologia nostra), limits the degree to which God can be known by sinful man and became important in later Reformed and Lutheran theology.