The Defenestrations of Prague (Czech: Pražské defenestrace, German: Prager Fenstersturz, Latin: Defenestratio Pragensis) were three incidents in the history of Bohemia in which people were defenestrated (thrown out of a window). Though already existing in Middle French, the word defenestrate is believed to have first been used in English in reference to the episodes in Prague in 1618 when the disgruntled Protestant estates threw two royal governors and their secretary out of a window of the Hradčany Castle and wrote an extensive apologia explaining their action. In the Middle Ages and early modern times, defenestration was not uncommon—the act carried elements of lynching and mob violence in the form of murder committed together.

The first governmental defenestration occurred in 1419, the second in 1483 and the third in 1618, although the term "Defenestration of Prague" more commonly refers to the third. Often, however, the 1483 event is not recognized as a "significant defenestration", which leads to some ambiguity when the 1618 defenestration is referred to as the "second Prague defenestration". The first and third defenestrations helped to trigger prolonged religious conflicts, either inside Bohemia (the Hussite Wars, 1st defenestration) or beyond (Thirty Years' War, 3rd defenestration), while the second helped establish a religious peace in the country for 31 years (Peace of Kutná Hora, 2nd defenestration).

The First Defenestration of Prague involved the killing of several members of the city council by a crowd of Czech Hussites on 30 July 1419. Jan Želivský, the priest of the Church of the Virgin Mary of the Snows, led his congregation on a procession through the streets of Prague to the New Town Hall on Charles Square. The town council members had refused to exchange their Hussite prisoners. While they were marching, a stone was thrown at Želivský from the town hall and allegedly hit him. This enraged the mob and they stormed the town hall. Once inside the hall, the group defenestrated the judge, the burgomaster, and several members of the town council, killing them all.

The First Defenestration led pro-Hussite Bohemian nobles to take control of Bohemia, and the Pope responded by declaring a crusade against "Wycliffites, Hussites and all other heretics in Bohemia", starting the prolonged Hussite Wars.

This defenestration took place on 24 September 1483 during the storms of the Prague population during the reign of King Vladislaus II of Hungary. He was king of Bohemia at that time but he became the ruler of Moravia and Hungary only after Matthias Corvinus died in 1490.^{[citation needed]}

It was then that the party of the Communion under both kinds, fearing for their influence, carried out a violent coup in the Old and New towns and Malá Strana. The Old Town Burgomaster and the dead bodies of seven New Town councilors were defenestrated from the respective town halls.^{[citation needed]} The coup in Prague contributed to the limitation of ruling power and prevented the resumption of pre-Hussite conditions.

On 6 October 1483, three Prague municipalities signed a treaty on unity and common action, which brought the dominion of the Utraquism. The development then led to religious reconciliation and the declaration of equality of both churches at the Kutná Hora Assembly in 1485.

This defenestration significantly influenced the history of Europe and led to the Thirty Years' War.