Moctezuma (c. 1466 – June 1520), also known by a number of variant spellings including Montezuma, Moteuczoma, Motecuhzoma and referred to in full by early Nahuatl texts as Motecuhzoma Xocoyotzin, is the ninth tlatoani or ruler of Tenochtitlan, reigning from 1502 to 1520.

The first contact between indigenous civilizations of Mesoamerica and Europeans takes place during his reign, and he is killed during the initial stages of the Spanish conquest of Mexico, when Conquistador Hernán Cortés and his men fight to escape from the Aztec capital Tenochtitlan.

During his reign the Aztec Empire, reaches its maximal size.

Through warfare, Moctezuma II expands the territory as far south as Xoconosco in Chiapas and the Isthmus of Tehuantepec, and incorporates the Zapotec and Yopi people into the empire.

He changes the previous meritocratic system of social hierarchy and widens the divide between pipiltin (nobles) and macehualtin (commoners) by prohibiting commoners from working in the royal palaces.

The portrayal of Moctezuma in history has mostly been colored by his role as ruler of a defeated nation, and many sources describe him as weak-willed and indecisive.

The biases of some historical sources make it difficult to understand his actions during the Spanish invasion.

He had eight daughters, including Doña, and Isabel Moctezuma — and eleven sons, among them Chimalpopoca (not to be confused with the previous huey tlatoani) and Tlaltecatzin.