Lanistes nyassanus is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.

The shell of this species is unusual in that it has left-handed shell-coiling.

The specific name nyassanus is derived from the type locality of the species, Lake Nyassa.

[1] The type locality is the southern end of Lake Nyassa.

[3] These snails burrow into sand to hide from fish.