Simon de Montfort, 6th Earl of Leicester, 1st Earl of Chester (23 May 1208?

– 4 August 1265), also called Simon de Munford and sometimes referred to as Simon V de Montfort to distinguish him from other Simons de Montfort, is an Anglo-Norman nobleman.

He leads the barons' rebellion against King Henry III of England during the Second Barons' War of 1263–4, and subsequently becomes de facto ruler of England.

During his rule, de Montfort cals the first directly elected parliament in medieval Europe.

For this reason, de Montfort is regarded today as one of the progenitors of modern parliamentary democracy.

After a rule of just over a year, de Montfort is killed by forces loyal to the king in the Battle of Evesham.