The Diocese of Urgell is a Latin Church diocese of the Catholic Church in Catalonia (Spain) and Andorra in the historical County of Urgell, with origins in the fifth century AD or possibly earlier. It is based in the region of the historical Catalan County of Urgell, though it has different borders. The seat and Cathedral of the bishop are situated in la Seu d'Urgell town. The state of Andorra is a part of this diocese.

Andorra, officially the Principality of Andorra, is a sovereign landlocked country on the Iberian Peninsula, in the eastern Pyrenees, bordered by France to the north and Spain to the south. Believed to have been created by Charlemagne, Andorra was ruled by the count of Urgell until 988, when it was transferred to the Roman Catholic Diocese of Urgell. The present principality was formed by a charter in 1278. It is currently headed by two co-princes: the bishop of Urgell in Spain and the president of France. Its capital and largest city is Andorra la Vella.