Physalaemus nanus is a species of frog in the Leptodactylidae family. It is endemic to Brazil. Its natural habitats are subtropical or tropical moist lowland forests, intermittent freshwater marshes, rural gardens, heavily degraded former forest, irrigated land, seasonally flooded agricultural land, and canals and ditches. It is threatened by habitat loss. Order: Anura, Family: Leptodactylidae.