This church is dedicated to Saint Eufemia, a saint who was martyred during the reign of Emperor Hadrian. In the year 1060, centuries after her death, a shepherdess discovered a tomb in Campelo, from which a hand with a gold ring on one of its fingers was sticking out. The woman picked it up and lost her speech, only recovering it after returning the jewel to the hand that held it. According to legend, a voice was then heard claiming that the tomb of Saint Euphemia was there.
The remains were moved and buried under the altar of the hermitage of Santa Mariña, between the dioceses of Braga and Orense. In 1159, the bishop of Orense, Pedro Seguín, with the help of a neighbour from Manín, attempted to transfer the body of the saint to the city's cathedral, which was opposed by the parishioners of Braga, giving rise to a dispute between the two dioceses. In order to resolve the dilemma, the decision was taken to place the urn with the saint's body in a cart pulled by oxen and to bury her remains in the place where the animals were going. The oxen made their way to Orense, stopping in the area of Seijalvo, where a cross was erected and from where the remains were taken to the capital, which explains the prominence that Saint Eufemia receives in the city.
The Church of Santa Eufemia was built in 1653 thanks to the Order of the Society of Jesus as part of a Jesuit school and, in 1767, it became a parish church of the Diocese of Orense. It is also, together with Santa María Madre, the largest church in the city.
On the outside, it is characterised by its monumentality with a concave shape, to establish a relationship between the central part and the sides, and two giant pairs of composite Ionic columns, which flank the large central niche with the image of the saint.
On the main façade of the church there are two identical coats of arms, one on the left and the other on the right, both dating from the 18th century. Each of these coats of arms is arranged in six sections.
Inside the church, the main altar, from the old church of San Francisco, stands out. In addition, during the French invasion it suffered a great deal of damage and later served as a refuge for Portuguese soldiers during the First Carlist War. It was inaugurated for worship on 26 May 1683. The church was the second one built on the site by the sons of San Ignacio de Loyola. The interior is characterised by its low Baroque influence, with strong classicist reminiscences. It has a Latin cross floor plan with three longitudinal naves, the side naves being lower, and it has a transept and a main chapel, all of which are inscribed in a rectangle.