The genus was named in 1995 by Stafford Howse and Andrew Milner. The type species is Plataleorhynchus streptophorodon. The genus name is derived form Platalea, the spoonbill, and Greek rhynchos, "snout", in reference to the distinctive form of the front of the skull. The specific name is derived from Greek streptophoros, "collared", and odon, "tooth", referring to the tooth form. The authors classified Plataleorhynchus as a member of the Ctenochasmatidae, a group containing many filter feeders. David Unwin in 2005 placed it in the subgroup of the Gnathosaurinae.