The diocese of Badajoz was a Roman Catholic ecclesiastical territory in Spain, created in 1255. In 1994 it became the Archdiocese of Mérida-Badajoz.
The Diocese or Archdiocese of Mérida (dioecesis Emeritensis) was a Catholic and Arian see centred on the Spanish city of Mérida during the periods of Roman and Visigothic rule. Mérida was also the provincial capital of Lusitania.
The see prospered in the late 5th century under Zeno, a Greek, who was offered greater authority in order to defend the province from Suevic raids. At about that time the diocese fell under the control of the Visigoths and it remained a Visigothic see until the Moorish conquest of 711. Throughout that period, however, it only ever had two Gothic bishops: Masona and his successor Renovatus in the late sixth and early seventh centuries. In the mid-sixth century the see became the richest in Spain through the private wealth of bishops Paul and Fidelis, Greek uncle and nephew. Under these four, the city was ruled de facto by the bishops independent of the central government, a situation which led to conflict between the Arian king Leovigild and his bishop, Sunna.