The Defenestrations of Prague were three incidents in the history of Bohemia in which people were defenestrated. 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.

Defenestration is the act of throwing someone or something out of a window. The term was coined around the time of an incident in Prague Castle in the year 1618 which became the spark that started the Thirty Years' War. This was done in "good Bohemian style", referring to the defenestration which had occurred in Prague's New Town Hall almost 200 years earlier, and on that occasion led to the Hussite war. The word comes from the Neo-Latin de- and fenestra.