The role of gelatinous zooplankton (GZ) as prey in marine food webs may be underestimated because they have low calorific value and are difficult to identify in predators’ guts. Many endoparasites infect multiple hosts during their life-cycle, with the final (usually vertebrate) host acquiring parasites by consuming intermediate hosts. Parasites, therefore, may be useful tracers of trophic links. We tested the utility of parasites for identifying vertebrate predators of GZ. 384 GZ, including medusae, ctenophores, salps and heteropods were collected from southeast Queensland waters and during voyages aboard RV Investigator. Parasites (mainly trematode metacercariae) were dissected from the GZ and ITS2 rDNA and cox1 mtDNA data generated for all host/parasite combinations. Trematode sequence data from GZ were compared to a database of sequences of adult trematodes from fishes and to relevant GenBank sequences. Sequences from multiple GZ parasites matched those of parasites from pelagic and inshore teleost fishes. Some fishes were known GZ predators but others, including several tropical pomacentrids, were novel, and may be opportunistic GZ predators. Our results highlight that GZ are a major food source for some fish, that parasites are novel and useful tracers of diet, and that GZ are important vectors of parasites to fishes.