The Medieval Inquisition is a series of Inquisitions (Catholic Church bodies (charged) with suppressing heresy) from around 1184, including the Episcopal Inquisition (1184-1230s) and later the Papal Inquisition (1230s). The Medieval Inquisition was in response to large popular movements throughout Europe considered apostate or heretical to Christianity, in particular Catharism and Waldensians in southern France and northern Italy. These were the first inquisition movements of many that would follow.

The Medieval Inquisitions were in response to growing religious movements, in particular the Cathars, first noted in the 1140s in southern France, and the Waldensians, starting around 1170 in northern Italy. Individual "Heretics", such as Peter of Bruis, had often challenged the Church. However, the Cathars were the first mass heretical organization in the second millennium that posed a serious threat to the authority of the Church. This article covers only these early inquisitions, not the Roman Inquisition of the 16th century onwards, or the somewhat different phenomenon of the Spanish Inquisition, which was under the control of the Spanish monarchy, though using local clergy. The Portuguese Inquisition and various colonial branches followed the same pattern.