Diplostomum pseudospathaceum is a species of trematode in the family Diplostomidae.

It is a type of fluke infecting the eyes of some species of fish, altering their movement patterns to suit its needs at different stages of development.

[3] When infecting a fish, it quickly moves into the fish's eye lenses, as they lack blood circulation, so the parasite is protected there from the host's immune system.

[3] This latter trait is probably responsible for the parasite's broad range of fish host species.

[5] Intermediate hosts of Diplostomum pseudospathaceum include: It is known to infect Larus ridibundus, the black-headed gull, as a definitive host.