Several members of the Psylloidea vector pathogens of agricultural crops in the Pacific Northwest (“PNW”) U.S. states of Idaho, Montana, Oregon and Washington. These crop-production concerns have renewed interest in the biodiversity of this superfamily in the region. We compiled a checklist of this group by examining published records and collections. This revealed 118 species of psyllids from 23 genera; 29 of these species had not been previously reported in the PNW. Our species list provides a useful starting point for entomologists investigating the ecology of emerging insect-transmitted plant pathogens in the region.