The Crisis of the Late Middle Ages was a series of events across Europe during the late Middle Ages. These events involved extensive demographic collapse, political instability, and religious upheaval. Collectively, they marked an end to a centuries-long period of relative stability in Europe, and reshaped regional societies. This crisis period coincides with a shift in the regional climate from the Medieval Warm Period to the Little Ice Age.

The events of the Crisis include the Great Famine of 1315–1317 and the Black Death of 1347–1351, which caused very high mortality across the region. Population did not rise to pre-crisis levels until around 1500.

Warfare and popular revolts proliferated across the continent, including the English Wars of the Roses, the French Armagnac–Burgundian Civil War, the Hundred Years' War, the Byzantine–Ottoman wars, and the Bulgarian–Ottoman wars. The Catholic Church underwent the Western Schism, and the Holy Roman Empire lost much of its central authority following the Great Interregnum (1247–1273), to the advantage of the German princes.

The expression "crisis of the late Middle Ages" is commonly used in western historiography, especially in English and German, and somewhat less in other western European scholarship, to refer to the array of crises besetting Europe in the 14th and 15th centuries. The expression often carries a specification such as the urban crisis of the late Middle Ages, or the cultural, monastic, religious, social, economic, intellectual, or agrarian [de] crisis, or a regional focus such as the Catalan or French crisis.

By 1929, the French historian Marc Bloch was already writing about the effects of the crisis, and by mid-century there were academic debates being held about it. In his 1981 article "Late Middle Age Agrarian Crisis or Crisis of Feudalism?", Peter Kriedte reprises some of the early works in the field from historians writing in the 1930s, including Marc Bloch, Henri Pirenne, Wilhelm Abel, and Michael Postan. Referring to the crisis in Italy as the "Crisis of the 14th Century", Giovanni Cherubini alluded to the debate that already by 1974 had been going on "for several decades" in French, British, American, and German historiography.

Arno Borst (1992) states that it "is a given that fourteenth century Latin Christianity was in a crisis", goes on to say that the intellectual aspects and how universities were affected by the crisis is underrepresented in the scholarship hitherto ("When we discuss the crisis of the late Middle Ages, we consider intellectual movements beside religious, social, and economic ones"), and gives some examples.

Some question whether "crisis" is the right expression for the period at the end of the Middle Ages and the transition to Modernity. In his 1981 article "The End of the Middle Ages: Decline, Crisis or Transformation?" Donald Sullivan addresses this question, claiming that scholarship has neglected the period and viewed it largely as a precursor to subsequent climactic events such as the Renaissance and Reformation.

In his "Introduction to the History of the Middle Ages in Europe", Mitre Fernández wrote in 2004: "To talk about a general crisis of the late Middle Ages is already a commonplace in the study of medieval history."