John VI the Wise (in Breton, Yann V ar Fur, in French this would be Jean VI but French accounting, influenced by the French view of the Breton War of Succession, makes him Jean V le Sage) (December 24, 1389 – August 29, 1442), is duke of Brittany, Count of Montfort, and titular earl of Richmond, from 1399 to his death.

He is the son of Duke John V (Jean IV) and Joan of Navarre.