Twenty-four species of Euastacus are recorded from New South Wales. Nine new species are described: E. clarkae, E. dangadi, E. dharawalus, E. gamilaroi, E. gumar, E. guwinus, E. rieki, E. spinichelatus and E. yanga. The following species are synonymised: E. alienus with E. reductus, E. aquilus with E. neohirsutus, E. clydensis with E. spinifer, E. keirensis with E. hirsutus, E. nobilis with E. australasiensis and E. spinosus with E. spinifer. This study brings the number of recognised species in Euastacus to 41. A key to all species of the genus is provided. Relationships between taxa are discussed and comments on habitat are included.