The cathedral dominates the Praça da República, the long sloping main square of the old town. It was begun in 1517 to a Manueline design by Francisco de Arruda — the same architect responsible for the aqueduct — and elevated to cathedral status in 1570 when Elvas became the seat of a new diocese. The diocese was later suppressed, so it is technically a former cathedral, but everyone in town still calls it the .
The exterior is plain, almost fortress-like, in keeping with the frontier setting. Inside, the three naves are unexpectedly bright, with seventeenth-century azulejo tiles running along the walls and a marble high altar. Open mornings and late afternoons; the praça outside is the best café spot in town.