Potamonautes isimangaliso is a species of freshwater crustacean in the family Potamonautidae.

It is endemic to iSimangaliso Wetland Park, South Africa.

Its natural habitat are the ephemeral wetlands fringing the western shores of False Bay.

Molecular DNA analyses were required to distinguish it from the similar and rather variable P. lividus, which occurs further inland.

It is further distinguished by its unique suite of carapace characters, besides its colouration and size.