The Ranchi Catholic Archdiocese (Latin: Archidioecesis Ranchiensis), with roots of activities tracing to more than 150 years, currently comprises the districts of Ranchi and Lohardaga of Jharkhand state, India. It was established by a decree of the Holy See, dated 25 May 1927, when it was separated from the Calcutta Archdiocese to form a new Diocese, with its Episcopal seat at Ranchi. In 1953 it was elevated to be an archdiocese. As declared on its website, Roman Catholic Archdiocese of Ranchi "subscribes to ahimsa and satyagraha".
The dioceses Daltonganj, Dumka, Gumla, Hazaribag, Jamshedpur, Khunti, Port Blair and Simdega are suffragans of the archdiocese.
Cardinal Telesphore Toppo is bishop of the archdiocese since 1985. Vincent Barwa is auxiliary bishop since 2004. Binay Kandulna was appointed auxiliary bishop in February 2009.