The Sri Lankan sambar deer ("Rusa unicolor unicolor") is a subspecies of sambar deer that lives in Sri Lanka. This subspecies is one of the largest sambar deer species with the largest antlers both in size and in body proportions. Large males weight up to 270–280 kg. Sri Lankan sambar live in lowland dry forests and mountain forests. Large herds of sambar deer roam the Horton Plains National Park, where it is the most common large mammal.