The Purple-bibbed Whitetip is distributed along the Pacific slope of the Andes from Colombia to Ecuador. See the distribution map at Birdlife International. It is fairly inconspicuous and is found in the lower growth and forest borders at between 700 and 1,600 metres.

The Purple-bibbed Whitetip is restricted to the west slope of the Andes while its congener, the Rufous-vented Whitetip U. ruficrissa is restricted to the eastern slope.

The specific name refers to an English taxidermist who specialised in hummingbirds, Benjamin Leadbetter (1773-1851).