Engystomops petersi (common name: Peters' dwarf frog) is a species of frog in the Leptodactylidae family.It is found in Amazonian Colombia, Ecuador, and Peru. It is morphologically similar to its sibling species, Engystomops freibergi, and for a period the latter was considered to be a junior synonym of Engystomops petersi. There are records from the Guianas that have not yet been allocated to either species. Divergence of these two species seems to have been driven by behavioural isolation related to male call characteristics more than geographic isolation.