Zemelanopsis trifasciata is a species of freshwater snail in the family Melanopsidae.

It is endemic to New Zealand, where it is found in fresh and brackish water habitat throughout the country.

[3] The type locality is "Waitanga Falls", in Waitangi, Northland, Bay of Islands, New Zealand.

The height of the shell is 18–30 mm.

[4] It lives in streams and rivers near their estuaries.