Euastacus is a genus of freshwater crayfish known as "spiny crayfish". They are found in the south-east of the Australian mainland, along with another genus of crayfish, Cherax. Both genera are members of the Parastacidae family, a family of freshwater crayfish restricted to the Southern Hemisphere.

Euastacus is a genus of freshwater crayfish known as "spiny crayfish". They are found in the south-east of the Australian mainland, along with another genus of crayfish, Cherax. Both genera are members of the Parastacidae family, a family of freshwater crayfish restricted to the Southern Hemisphere.