Walter II Grenier (French: Gautier; died 1189×91) was the Lord of Caesarea, succeeding his older brother, Guy, between 1176 and 1182.
That year, with the consent of his sister, Julianne, and her husband, Guy of Beirut, he sold the casale of Galilaea, near Caesarea, to the military Order of the Hospital for 5,000 bezants.
This act was drawn up by the royal chancellor, Archbishop William of Tyre, at the Haute Cour in Jerusalem and was witnessed by the highest-ranking men in the kingdom: King Baldwin IV, Lord Baldwin II of Ramla (Walter's step-father), Lord Balian of Ibelin, Count Guy of Jaffa and the constable, Amalric of Lusignan.
[1] In July 1187, Walter was one of the barons—along with Count Raymond III of Tripoli, Count Joscelin III of Edessa, Lord Reginald of Sidon and Raymond de Gibelet—who negotiated a treaty with Genoa to defend the city of Tyre from Saladin.
The Lignages d'Outremer states that "Walter was killed at the recovery of Acre" (Gautier fu occis ou recouvrer d'Acre), and the French historian Louis de Mas Latrie assumed that this meant on the last day of the siege, when the city fell.