We describe Scytalopus perijanus (Perijá Tapaculo), a new species in the family Rhinocryptidae (suborder Tyranni) found in humid montane and elfin forests (1,600–3,225 m elevation) in the Serranía de Perijá of Colombia and Venezuela. Although specimens of this taxon have been available in museums since 1941, they were not carefully studied and were ascribed to different taxa of the latebricola and atratus groups. We obtained a modern series of specimens that, coupled with analysis of vocal and genetic data, clarified this taxonomic puzzle. The new Scytalopus exhibits distinctive morphological and vocal traits with respect to all other known species and represents a differentiated evolutionary lineage within a clade of northern species, including S. meridanus, S. caracae, and S. latebricola. The new species has not been recorded in sympatry with any other Scytalopus, but it may overlap at lower elevations with S. atratus nigricans, although each uses different microhabitats. Ecological niche modeling indicates that the new species currently has a restricted geographic range within the Serranía de Perijá, where large extents of natural habitat have been cleared and fragmented, particularly on the Colombian slopes. Scytalopus perijanus, however, is uncommon to fairly common in forest fragments, tall secondary forest patches, elfin forest, and paramo vegetation at the treeline.