We describe Scytalopus alvarezlopezi from the Western Andes of Colombia. The new species forms part of a distinctive clade of Scytalopus tapaculos (Rhinocryptidae) that also includes S. robbinsi from Ecuador and S. stilesi and S. rodriguezi, which occur on the Central and Eastern Andes of Colombia. S. alvarezlopezi is easily diagnosable from its near relatives by its song and mitochondrial DNA; differences in plumage exist but are more subtle. The species inhabits dense understory vegetation on the floors and lower slopes of ravines in cloud forest at elevations of 1,300 to 2,100 m. On the Pacific slope, its altitudinal distribution is sandwiched between those of S. chocoensis (below) and S. vicinior (above); the latter in turn is replaced higher up by S. spillmanni and S. latrans, but S. alvarezlopezi also occurs at ∼2,000–2,100 m on eastern slopes just below the low ridgeline. All of the latter species are distinguished by vocal and plumage characters. Marked sexual differences in plumage exist in stilesi, but females have yet to be collected for alvarezlopezi and rodriguezi. We consider that S. alvarezlopezi is not threatened at present, but could be potentially vulnerable due to its restricted distribution; it is endemic to Colombia.