Atelopus petersi is a species of toads in the family Bufonidae. It is endemic to Ecuador and is known from the Cordillera Oriental in the Napo Province and more provisionally, in the Chimborazo Province. The specific name petersi honors James A. Peters, an American zoologist who collected the first specimens of this species in 1962 and provided a description under the name Atelopus pachydermus. Common names Peters' stubfoot toad and Peters' jambato toad have been coined for it.
Adult males measure 35–42 mm (1.4–1.7 in) and adult females 43–50 mm (1.7–2.0 in) in snout–vent length. The snout is acuminate. The tympanic membrane, annulus, and stapes are absent. The fingers have lateral fringes but no webbing whereas the toes are webbed. The dorsum has a yellow to orange pattern on black background, and may be almost entirely black. Warts and pustules may have white tops. The flanks are white. The venter is white and may have black marks, or is uniform orange to reddish orange.