The Collegiate Church of Santa María del Campo is a Romanesque-Gothic style church, constructed between the 12th and 14th centuries. It was built outside the old city walls, hence its name, del Campo.

The façade was modified in 1880. It has three doorways. The main portico, which is the original one, has been preserved. The rose window is ogival, from the 14th century and the bell tower from the 15th century belongs to the ogive/Gothic style. In the atrium, there is a cross from the late 15th century. It has medieval tombs in the naves and interesting polychrome stone images of the Annunciation. The altar is made of embossed silver.

The church is also known as Santa María del Mar, as it was the old church of the seafarers' guild. For a long time, it was the custom among sailors to visit this church as soon as they returned from the sea, as a sign of gratitude for having arrived safely to the port.

In 1441, it was granted the status of collegiate church by the Archbishop of Compostela, Don Lope de Mendoza.

It has been listed as a Cultural Heritage Site since 1931.