Olallamys albicaudus (Günther, 1879) is a rodent called the white-tailed Olalla rat. It is a medium-sized rat with soft, long pelage and a tail with a whitish tip. The dorsum is bright reddish-brown, and the venter is whitish. It is endemic to the Andes region of Colombia and despite its wide distribution in the country, O. albicaudus is known from only a few museum specimens associated with 12 confirmed localities within Colombia. Globally, it is considered “Data Deficient” by the International Union for Conservation of Nature.