The Sundaic mountain leopoldamys (Leopoldamys ciliatus) is a species of rodent from the family Muridae. It was formerly considered a subspecies of Edwards's long-tailed giant rat, and it has one synonym: Leopoldamys setiger.
The Sundaic mountain leopoldamys occurs in the montane forests of Sumatra, Indonesia, and peninsular Malaysia, typically at elevations above . It is a terrestrial, possibly arboreal species occurring in primary and degraded tropical moist forest.
The Sundaic mountain leopoldamys is listed as Least Concern by the IUCN Red List due to a wide distribution, presumed large population, occurrence in a number of protected areas, degree of tolerance for habitat modification, and unlikely declination at the speed to qualify for a more threatened listing. However, due to deforestation of its habitat for timber, firewood, and agricultural land, its population is decreasing.