The Diocese of Les Cayes (; ; ), erected 3 October 1861, is a suffragan of the Archdiocese of Port-au-Prince.
The ecclesiastical province of Port-au-Prince (the archdiocese and the four suffragan dioceses of Cap Haïtien, Les Gonaïves, Les Cayes, and Port-de-Paix) dates from the reorganization following upon the Concordat of 1860 between Pope Pius IX and the Republic of Haiti.