Although animal tissues are composed of numerous chemical elements, most ecological stoichiometry studies focus on carbon, nitrogen, and phosphorus. To assess whether additional insights could be gleaned from encompassing more elements, we gathered freshwater fish body composition data (P, Ca, Na, K, Mg, Mn, Fe, Zn, Sr) from 38 species in tropical and temperate geographic locations. Patterns in body stoichiometry were examined in relation to the species taxonomic order, trophic guild, and region. Across fish species, we expected to find minimal interspecific variation in ratios of many elements due to their coupled use in key molecules and structural materials (i.e., functional associations such as bone or osmoregulation). Overall, our survey reveals extensive variation in fish stoichiometric phenotypes both within and across fish taxonomic orders and geographic regions. Taxonomic affiliation strongly affected patterns in body stoichiometry, such as the high concentrations of the elements used in bones (Ca, P, Mn, Sr) among the armored catfish. There were clear differences among geographic regions in Na, K, Fe, and Mn concentrations across fish species. Although we have found fish stoichiometry to significantly differ between trophic guilds for some elements (P, Mn, Sr, Mg, Na, Fe), it seems this result was driven by taxonomic order and the environment. The present study helps deepen our understanding of stoichiometric patterns in fishes by highlighting the role of taxonomic affiliation and the environment, in a large fish dataset encompassing distinct geographic regions, taxonomic orders, and trophic guilds.