Deep-sea squids (order Oegopsida) are recognised for their integral role in marine ecosystems, which can be investigated through detailed trophic studies. Gould’s arrow squid (Nototodarus gouldi) is a commercially exploited species in the southwest Pacific. Although prey composition has been reported from Australia, no research to date has been published on this species’ diet in Aotearoa, New Zealand. This integrative study combined morphological, DNA analyses and helminth parasite identification to provide the first data on the prey of N. gouldi in Aotearoa, New Zealand. Gut contents were visually screened for parasites and hard parts of prey remains—including otoliths, eye lenses, squid beaks, crustacean exoskeletons and soft tissues. The conservative DNA barcode region (cytochrome c oxidase subunit I [COI]) was sequenced for representative pieces of soft tissue (which could not be visually identified). Overall, 26 species from across six phyla were reported, including 18 novel species herein reported for the first time in the diet of N. gouldi. This baseline information on the prey species and parasites of N. gouldi may serve as a foundation for ecosystem-based fishery management and understanding trophic interactions and prey dynamics within the south Tasman region.