I describe a new species of Stenocercus from the lowlands of southwestern Ecuador and northwestern Peru. The new species differs from other Stenocercus by the combination of the following characters: posterior circumorbitals present, one row of supraoculars enlarged, posterior head scales enlarged, projecting angulate temporals absent, canthals two, ventrals smooth, posthumeral and postfemoral mite pockets shallow, dorsolateral crests absent, inscriptional ribs not articulating midventrally, throat yellow and venter lavender in males. Some evidence suggests that the new species is closely related to Stenocercus iridescens, which occurs allopatrically in the lowlands of western Ecuador and southwestern Colombia.