The diets of 21 terapontid species from freshwater environments in northern Australia were investigated to determine the similarity and dissimilarity among species and the extent of any ontogenetic shifts. Distinct ontogenetic dietary shifts occurred in all species for which sufficient data were available, with many species passing through several discrete trophic categories during their life histories. Diets of all juvenile terapontids were similar, mainly comprising aquatic insects and zooplankton. Larger size classes of terapontids diverged into a broad spectrum of feeding groups comprising carnivorous dietary modes (including piscivory and lepidophagy), omnivory (including frugivory and consumption of allochthonous prey), herbivory and detritivory. The results indicate that the terapontids represent Australia's most trophically diverse freshwater fish family.