The serrated hinged terrapin (Pelusios sinuatus) is a species of turtles in the Pelomedusidae family. It is found in tropical East Africa in lakes and rivers. It can often be seen basking on logs, rocks or mud banks, or even on the backs of sleeping hippopotami. It eats water snails, soft-weed, and insects. It is the largest species in the genus Pelusios, with a carapace length of up to 55 cm. Females are larger than males. Males can also be distinguished by their slightly longer tails.
For defence, the hinged plastron closes to protect the head and forelimbs, and the terrapin also secretes a foul odour when threatened.