Arroyo de San Serván is a municipality in the province of Badajoz, in the autonomous community of Extremadura, Spain. It lies within the comarca of Tierra de Mérida–Vegas Bajas, in the western part of the country near the Portuguese border.
According to the 2012 census (INE), the municipality had a population of 4,267 inhabitants. The town's first census was held in 1842, as part of Badajoz.