The Cathedral Basilica of Santiago in Bilbao is the Catholic temple that since 1949 has housed the headquarters of the Diocese of Bilbao.

It was built between the last quarter of the fourteenth century and the beginning of the sixteenth in the Gothic style, although its facade and tower are the result of a profound reconstruction undertaken in the nineteenth century in the neo-Gothic style.

The Cathedral takes its name from the patron saint of Bilbao, the Apostle Santiago el Mayor, in connection with the passage through the city of a coastal branch of the Camino de Santiago.

It is the most monumental Gothic church in Vizcaya and also serves as a parish.

In 1819 it obtained the rank of minor basilica, being the first church to obtain this title in the Basque Country.

The current building succeeded two previous ones in the same location and with the same dedication. The first was prior to 1300, the date of the founding of the town by D. Diego López V de Haro through the Carta Puebla, and it had an exterior necropolis located around the head wall. The second temple was basically an extension of the previous one, forced before the demographic growth of the urban nucleus. This second temple was ephemeral, since in 1374 it was destroyed in a terrifying fire, after which Pope Gregory XI gave indulgences to those who gave alms for the erection of the new temple, according to a more ambitious architectural project.

The cathedral built after the disaster of 1374 is the result of a long and cumulative period of different elements: the church, the cloister, the portico, the sacristy and the tower-facade. Begun at the end of the 14th century, around 1397, in accordance with the then prevailing classical Gothic style, the works slowly continued for a long century.

Towards the middle of the 15th century, the clerestory and the ambulatory with its five central chapels were finished; in the second half of the century, work was carried out on the other chapels in the head and later, already on the border with the 16th century, on the side chapels of the nave. At the same time, the cloister and the Puerta del Ángel were built, which gives access from the street and which already incorporates elements of the flowery Gothic.

In the first third of the twentieth century the cloister was restored and in the final years of the century, after the devastating floods of 1983, when the waters of the Nervión-Ibaizábal invaded the entire Old Town of Bilbao and flooded the Cathedral, actions were taken throughout the whole, repairing and cleaning the interiors and exteriors damaged by the flood.