The Roman Catholic Diocese of Constantine (-Hippone) (Latin: Dioecesis Constantinianus (-Hipponensis Regiorum), French: Diocèse de Constantine et Hippone) is a Roman Catholic diocese in the ecclesiastical province of Algiers in Algeria.

Before the enforcement of the Association law of 1901, the Lazarists, the Little Brothers of Mary and the White Fathers were active in the diocese.

It includes parishes in Constantine, Annaba, Skikda, Sétif, Béjaïa, Batna, and Tébessa.

The current pro-cathedral is the minor basilica Basilique Saint Augustin in Annaba (Hippo).

The former cathedral of the diocese is the Cathédrale Notre-Dame des Sept-Douleurs in Constantine.