The yellowish oryzomys is a South American rodent with yellowish to gray-brown dorsal fur and a long tail. It is recorded from dry mountains in western Ecuador and Peru and from the upper Marañón valley in northern Peru.
Its back is yellowish to gray-brown, while the underside is paler. It has small ears and a long tail, which may be uniformly colored or bicolored among individuals.
The species inhabits dry montane areas of western Ecuador and Peru, and is also recorded at higher elevations in the upper Marañón valley of northern Peru.
An extinction-risk assessment has not been added yet.