The Diocese of Port Pirie is a Latin Church ecclesiastical jurisdiction or diocese of the Catholic Church in Australia.

It is a suffragan in the ecclesiastical province of the metropolitan Archdiocese of Adelaide, erected in 1887 covering the Yorke and Eyre Peninsulas, Flinders Ranges, Nullarbor Plain, and Mid and Far North regions of South Australia, Australia.

The Diocese of Port Augusta was canonically erected by Pope Leo XIII on 10 May 1887, the same day the pope elevated the See of Adelaide to a metropolitan archdiocese and placed the new diocese in its province.

On 5 August 1951 the seat of the diocese was moved from Port Augusta to Port Pirie, with the name of the diocese being also changed.

[1] The following men have been Bishops of Port Pirie or any of its precursor titles:[2]