The Roman Catholic Diocese of Poreč and Pula (Croatian: Porečko-pulska biskupija; Latin: Dioecesis Parentina et Polensis; Italian: Diocesi di Parenzo e Pola) is a suffragan Latin diocese in the ecclesiastical province of the Metropolitan Archdiocese of Rijeka on Istria peninsula, in Croatia.

The Co-Cathedral is the Cathedral of the Assumption of the Blessed Virgin Mary in Pula.

Pelagije, in Novigrad, and Crkva Navještenja BDM, in Pićan.

As per 2014, it pastorally served 169,048 Catholics (79.5% of 212,561 total) on 2,839 km2 in 135 parishes with 108 priests (94 diocesan, 14 religious), 1 deacon, 78 lay religious (48 brothers, 30 sisters) and 6 seminarians.

(all Roman rite; probably many Italians, notably in the early centuries)