Gracilinanus microtarsus (J. A. Wagner, 1842), called the Brazilian gracile opossum, is a small didelphid that is 1 of 6 species in the genus Gracilinanus. It is a sexually dimorphic, solitary marsupial that has a highly seasonal reproductive pattern. It inhabits Atlantic rain forests and semideciduous forests interspersed in the highly seasonal cerrado (savanna-like vegetation) in southeastern and southern Brazil. It prefers locations associated with low canopy cover and it also occurs in habitats altered by anthropogenic events. The species is classified as Least Concern by the International Union for Conservation of Nature and Natural Resources.