The Cathedral of the Assumption of Our Lady in Tuam is the seat of the Roman Catholic bishop of the local diocese. The city also has the Cathedral of Our Lady belonging to the Protestant Church of Ireland. It is a neo-gothic, three-nave building with a square tower above the entrance.
The cathedral was built in the first half of the 19th century. It was built of stone, modeled on English churches from the thirteenth and fourteenth centuries. It is a three-nave structure with a transept. In the walls of the transept there are large windows decorated with tracery. A square tower rises above the entrance. It is, like the corners of the nave and the upper parts of the side walls, finished with square turrets.
The interior is divided into naves with polygonal pillars supporting the cross-ribbed vault. In the courtyard there is a statue of Bishop John MacHale, who fought for the emancipation of Catholics in Ireland during his ministry.