The Diocese of Le Havre (Latin: Dioecesis Portus Gratiae; French: Diocèse du Havre [djɔsɛz dy ɑvʁ(ə)]) is a Latin diocese of the Catholic Church in France.

The diocese comprises the arrondissement of Le Havre in the department of Seine-Maritime, Normandy.

The diocese was created from territory of the Archdiocese of Rouen, and remains suffragan to the parent diocese.

The current bishop is Jean-Luc Brunin, appointed in 2011.

In 2021, in the Diocese of Le Havre there was one priest for every 8,128 Catholics.