Leith's softshell turtle (Nilssonia leithii ) is a species of turtle in the family Trionychidae. The species is found in peninsular Indian rivers including the Bhavani, Godavari, and Moyar Rivers. The type locality is Pune in India.
The specific name, leithii, is in honor of Andrew H. Leith, a physician with the Bombay Sanitary Commission.
Nilssonia leithii is intermediate between Nilssonia gangetica and Nilssonia hurum. It is like the former in the width of the interorbital apace, the comparatively short mandibular symphysis, and the markings of the head. It is like the latter in the longer and more pointed snout, the absence of a strong ridge on the inner alveolar surface of the mandible, and in the presence, in the young, of four or more dorsal ocelli, which are, however, smaller than in N. hurum.
Adults may attain a straight carapace length of 64 cm (25 in).
Leith's softshell turtle is endemic to peninsular India in the Indian states of Andhra Pradesh, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Tamil Nadu and Odisha
Nilssonia leithii preys on mosquito larvae, crabs, freshwater molluscs, and fish. They also sometimes feed on small aquatic vegetation.
The adult female N. leithii lays eggs in June. The eggs are spherical, and the diameter of each egg is 30 to 31 mm (1.2 in).