Chroomonas nordstedtii is a species of cryptophyte alga in the family Chroomonadaceae, named after the Swedish botanist Carl Fredrik Otto Nordstedt, a prominent phycologist of the nineteenth century who made significant contributions to the study of freshwater algae and desmids. Cryptophytes in the genus Chroomonas are small, biflagellate unicells widely distributed in freshwater and brackish environments globally, contributing to planktonic diversity and primary production. They are distinguished from other flagellate algae by their unique cryptophyte plastid, nucleomorph, and ejectosomes — proteinaceous coiled structures unique to the group. Chroomonas nordstedtii has been documented from European freshwater habitats, including Scandinavian localities that were well studied by Nordic phycologists in the classical period of algal taxonomy. The species is part of the diverse microalgal flora of boreal and temperate freshwater ecosystems. Cryptophytes contribute to planktonic food webs as prey for heterotrophic protists and small metazoans, and as high-quality dietary components in zooplankton feeding experiments. The species has not been assessed under IUCN criteria.