Leptolebias is a ray-finned fish genus of the killifish family Rivulidae. Like many of their relatives, they are rather ambiguously known as "pearlfish". They are endemic to the coastal areas of Brazil, where they inhabit ephemeral pools in tropical forests like the Mata Atlântica (or what remains thereof) and restinga. Rare and little-known, the entire genus seems to be close to extinction. Specifically, Leptolebias species have been found in two regions to date: between Maricá and Vila de Cava in Rio de Janeiro state, and between Itanhaém in southern São Paulo state and the Paranaguá bay catchment area in Paraná state.