Two new species of the genus Tripaphylus Richiardi in Anonymous, 1878 (family Sphyriidae) are described from elasmobranch hosts caught as bycatch within the Demersal and Timor Reef Fisheries which operate in the Northern Territory exclusive economic zone. Tripaphylus squidwardin. sp. was collected from Carcharhinus coatesi Whitley and had a prevalence of 11.6%. Tripaphylus dippenaaraen. sp. was collected from Rhizoprionodon acutus (Rüppell) and had a prevalence of 28.2%. The new species are distinguished from existing congeneric species by the body proportions and shape of the adult female and by the arrangement of lobes on the ventral surface of the cephalothorax.