The Black-and-white Monjita (Xolmis dominicanus) is a species of bird in the Tyrannidae family. It is found in Argentina, Brazil, Uruguay, and possibly Paraguay. Its natural habitats are subtropical or tropical dry lowland grassland, subtropical or tropical seasonally wet or flooded lowland grassland, arable land, and pastureland. It is threatened by habitat loss. This species is sometimes spearated in the monotypic genus Heteroxolmis.