Curia Regis is a Latin term meaning "Royal Council" or "King's court".

The Curia Regis in England was a council of tenants-in-chief and ecclesiastics that advised the king of England on legislative matters. It replaced its Anglo-Saxon predecessor, the Witenagemot, after the Norman invasion of 1066.

William of Normandy brought to England the feudal system of his native France. Thus, he granted land to his most important military supporters, who in turn granted land to their supporters, thus creating a feudal hierarchy. Those who held lands directly from the King were known as tenants-in-chief, and the territories they held were called manors. William I was an absolute ruler, but, as a matter of course, he sought the advice of the curia regis, before making laws.

The tenants-in-chief often struggled with their spiritual counterparts and with the King for power. In 1215, they secured from John the Magna Carta, which established that the King may not levy or collect any taxes (except the feudal taxes to which they were hitherto accustomed), save with the consent of this council. It was also established that the most important tenants-in-chief (the earls and the barons), as well as the ecclesiastics (archbishops, bishops and abbots) be summoned to the council by personal writs from the Sovereign, and that all others be summoned to the council by general writs from the sheriffs of their counties. John later repealed the Magna Carta, but Henry III reinstated it.

The royal council slowly developed into a Parliament. In 1265, Simon de Montfort, 6th Earl of Leicester, who was in rebellion against Henry III, summoned a parliament of his supporters without any or prior royal authorisation. The archbishops, bishops, abbots, earls and barons were summoned, as were two knights from each shire and two burgesses from each borough. Knights had been summoned to previous councils, but the representation of the boroughs was unprecedented. De Montfort's scheme was formally adopted by Edward I in the so-called "Model Parliament" of 1295. At first, each estate debated independently; by the reign of Edward III, however, Parliament had been separated into two Houses and was assuming recognisably its modern form.