The Marquis of Riestra's mansion is an eclectic building with art Nouveau elements from the late 19th century[1] located at 30 Michelena Street in Pontevedra, Spain.

The mansion was built for Francisco Antonio Riestra Vallaure after the purchase of several plots of land in the 1860s in Michelena Street, where he had fourteen buildings constructed.

[7] The Marquis of Riestra died in his mansion at 30 Michelena Street in the early hours of 17 January 1923, after having gone out by car the previous afternoon to A Caeira.

In 1931 the Riestra family lost their father's holding company to the businessman Pedro Barrié de la Maza.

[9] On 19 July 1932, the building passed into the hands of the Pastor Bank, housing the offices of this institution[10] and of the Fenosa electricity company, which belonged to the same group.

On 30 January 1990, the Xunta de Galicia's General Directorate of Heritage paid the public limited company Unión Fenosa a total of 235 million pesetas for the ground floor, the basement and a small interior garden, thus completing the acquisition of the building for the new offices of its Department of Economy and Finance.