We describe a new species of tody-tyrant of the genus Poecilotriccus, isolated in midelevation forests of the Cordillera de Colán and nearby mountains to the east in the northeastern Andes of Peru. The new species is allopatric from, and forms a probable superspecies with, the Rufous-crowned Tody-Tyrant (P. ruficeps), the nearest known populations of which inhabit the Cerro Chinguela of northern Peru. The geographic ranges of those sister taxa are divided by the North Peruvian Low, occupied by the Río Marañón, the major break in east-slope Andean forest between Venezuela and Bolivia. The new species and its allospecies, P. ruficeps are identical in color of the back and in lightness and hue of the crown, but are 100% separable in lightness, chroma, and hue of the belly; in color and pattern of the face; and in song. We infer that differences in vocalizations and facial markings would serve as premating reproductive isolating mechanisms should the two forms become sympatric.