Oradea has been, under the names of Várad (Nagyvárad since 1872) (in Hungarian), Veľký Varadín (in Slovakian) and Großwardein (in German), the see of several major denominational Christian church communities during its history.

From that epoch dates also the Hermes, now preserved at Győr, which contains the skull of King Ladislaus, and which is a masterpiece of the Hungarian goldsmith's art.

Bishop János Vitéz (alias Johann Vitíz von Zredna, 1445–1465) was one of the most distinguished and active promoters of Humanism in Hungary.

After the death of György Martinuzzi (1535–1551), the greatest of the bishops of Várad and the advisor of King János Szapolyai and Queen Isabella, the see deteriorated.

In 1777 part of its territory was split off to form the diocese of Satu Mare, with which it was reunited in 1930, only to see it reconstituted in 1941 and again suppressed in 1948.

The diocese was established within its present boundaries, drawn by Ceaușescu's Communist regime, on 18 October 1982, again without the reconstituted Satu Mare.