San Amaro is a municipality in the province of Ourense, within the autonomous community of Galicia in northwestern Spain. It belongs to the comarca (district) of O Carballiño, which lies in the northern part of the province.
The municipality takes its name as a homage to Saint Amaro, a figure venerated in Galician and broader Iberian religious tradition. As a Galician municipality, it forms part of the region's network of small local administrative units, known as concellos, which serve as the basic tier of local government in Spain.
Its location in Ourense places it within Galicia's inland territory, a landlocked province bordered by Lugo to the north, León and Zamora to the east, Portugal to the south, and Pontevedra to the west. The comarca of O Carballiño, to which San Amaro belongs, is situated in the province's northern interior.