Bulla fontinalis Linnaeus, 1758 (basionym) Physa fontinalis, common name the common bladder snail, is a species of air-breathing freshwater snail, an aquatic gastropod mollusc in the family Physidae.

The spiral has four to five whorls ( the last of which forms more than three-quarters of the shell height) and the apex is rounded.

This species is an opportunist inhabiting streams, rivers, ponds, lakes, springs, canals and irrigation ditches.

Some ‘species’ found in North America may be conspecific in which case the range could be Circumpolar Boreo-temperate.

This species is found in the Czech Republic,[2] Slovakia,[2] Germany, Poland, the Netherlands, Croatia[3] and others.