The Edict of Torda (Hungarian: tordai ediktum, Romanian: Edictul de la Turda, German: Edikt von Torda) was a decree that authorized local communities to freely elect their preachers in the Eastern Hungarian Kingdom of John Sigismund Zápolya. The delegates of the Three Nations of Transylvania – the Hungarian nobles, Transylvanian Saxons, and Székelys – adopted it at the request of the monarch's Antitrinitarian court preacher, Ferenc Dávid, in Torda (Romanian: Turda, German: Thorenburg) on 28 January 1568. Though it did not acknowledge an individual's right to religious freedom, in sanctioning the existence of a radical Christian religion in a European state, the decree was an unprecedented act of religious tolerance.

The Catholic and Eastern Orthodox churches had coexisted in the southern and eastern territories of the medieval Kingdom of Hungary for centuries. However, ideas that the Catholic Church regarded as heresy were not tolerated: the Hungarian Hussites were expelled from the country in the 1430s and the 1523 Diet of Hungary passed a decree that ordered the persecution of Lutherans. The latter decree was in practice ignored during the civil war that followed the Ottoman victory against the Hungarian army in the Battle of Mohács in 1526. After the Ottomans occupied the central regions of the medieval kingdom in 1541, they allowed the infant John Sigismund to rule the lands to the east of the river Tisza under the regency of his mother, Isabella Jagiellon. In the early 1540s the Diets acknowledged the right of the Three Nations to freely regulate their internal affairs. The Saxons regarded religion as an internal affair and ordered the introduction of the Lutheran Reformation in their settlements in 1544–1545. The Diet sanctioned the coexistence of the Catholic and Lutheran denominations only in 1557.

John Sigismund started to rule personally after his mother died in 1559. He was interested in religious affairs and organized a series of debates between the representatives of the different Protestant theologies. He converted from Catholicism to Lutheranism in 1562, and from Lutheranism to Calvinism in 1564. His court physician, Giorgio Biandrata, and Ferenc Dávid jointly persuaded him to also allow the public discussion of the doctrine of the Trinity. Sigismund accepted Dávid and Biandrata's Antitrinitarian views in 1567. The Edict of Torda was adopted at the following Diet. It stated that "faith is the gift of God" and prohibited the persecution of individuals on religious grounds. In practice, the edict only sanctioned the existence of four "received" denominations – the Catholic, Lutheran, Calvinist, and Unitarian Churches. Further religious innovations were prohibited during the reign of John Sigismund's successor, Stephen Báthory, but religious tolerance remained a distinguishing feature of the Principality of Transylvania (the successor state to John Sigismund's realm) in Early modern Europe.

The Catholic Church was facing a profound crisis in the Kingdom of Hungary at the end of the Middle Ages. Ideas that the Catholic Church regarded as heretical appeared in the late 14th century, primarily in the small towns. In the 1430s, young burghers who had studied at the University of Prague began teaching the theology of the Czech Jan Hus, despite his having been condemned to death for heresy at the Council of Constance. Two Hussite preachers completed the first Hungarian translation of the Bible in the early 1430s. Pope Eugene IV appointed the Franciscan James of the Marches to eradicate Hussitism in Hungary in 1436. The Hussites who survived the purge fled to Moldavia in 1439.

German burghers of Upper Hungary (now mostly in Slovakia) were the first to adopt Martin Luther's views in the early 1520s. Dozens of the German courtiers of Mary of Habsburg (the wife of Louis II of Hungary) also supported the ideas of the Reformation. However, the Hungarian noblemen remained hostile towards Lutheran theology, primarily because they wanted to secure the support of the Holy See against the Ottoman Empire. On 24 April 1523, the Diet of Hungary passed a decree that ordered the persecution and execution of Luther's followers in the entire kingdom.

The Ottoman Sultan Suleiman the Magnificent annihilated the Hungarian army in the Battle of Mohács in 1526. Louis II drowned in a nearby stream while fleeing from the battlefield. The majority of the Hungarian noblemen elected as king one of their number, John Zápolya, but the most powerful noblemen proclaimed Louis II's brother-in-law, Ferdinand of Habsburg, the lawful monarch, leading to a civil war that lasted nearly two decades.

Ferdinand and John reached a compromise in 1538. Each acknowledged the other's right to rule, but they also agreed that the kingdom was to be reunited under the rule of the one who survived the other. However, the childless John married Isabella Jagiellon, who gave birth to a son, John Sigismund, in 1540. Two weeks later, John died, but only after persuading his supporters to pledge that they would secure his infant son's rule. Keeping their word, they elected John Sigismund king in Buda in clear contradiction to the 1538 compromise. The royal election provoked a new invasion by Ferdinand's troops.

Taking advantage of the new conflict, Suleiman again invaded Hungary in 1541. He occupied the central region, but confirmed John Sigismund's rule in the lands to the east of the river Tisza as his vassal, creating an Eastern Hungarian Kingdom. The Estates of John Sigismund's realm acknowledged the situation and swore fealty to the child king and his mother.