Beddomeia tumida is a species of very small (4 4 mm (0.16 in)[2]) freshwater snail that has a gill and an operculum.

It is an aquatic operculate gastropod mollusc in the family Hydrobiidae, and is endemic to Australia.

[1] It had not been spotted for 120 years and was listed by the IUCN as "critically endangered but possibly extinct", when in late 2021 one was found by researchers in yingina/Great Lake in the Central Plateau of Tasmania.

A survey found 15 further snails.

This Hydrobiidae-related article is a stub.