Quia Emptores is a statute passed by the Parliament of England in 1290 during the reign of Edward I that prevented tenants from alienating their lands to others by subinfeudation, instead requiring all tenants who wished to alienate their land to do so by substitution. The statute, along with its companion statute Quo Warranto also passed in 1290, was intended to remedy land ownership disputes and consequent financial difficulties that had resulted from the decline of the traditional feudal system in England during the High Middle Ages. The name Quia Emptores derives from the first two words of the statute in its original mediaeval Latin, which can be translated as "because the buyers". Its long title is A Statute of our Lord The King, concerning the Selling and Buying of Land. It is also cited as the Statute of Westminster III, one of many English and British statutes with that title.

Feudalism, also known as the feudal system, was a combination of legal, economic, military, cultural, and political customs that flourished in medieval Europe from the 9th to 15th centuries. Broadly defined, it was a way of structuring society around relationships derived from the holding of land in exchange for service or labour.