John of the Grating (Latin: Johannes a Craticula, French: Jean de Châtillon; died 1163) was a Cistercian Bishop of Aleth.

His rights were restored, and the monks of Marmoutiers were obliged to cede the Church of St. Malo to the bishop.

During his tenure he had to deal with the strange heresy of the fanatical Éon de l'Étoile.

John tried by persuasion and instruction to disabuse of their heresy such of the enthusiasts as overran his diocese, and succeeded in converting many.

[4] John was buried in the Cathédrale Saint-Vincent-de-Saragosse de Saint-Malo, where his relics lie in a stone 12th-century sarcophagus overlooking the ambulatory.