Zooplankton productivity is a critical component of food web function, of which one poorly known factor is the influence of symbiotic interactions. Protists commonly form symbiotic associations with zooplankton, but their diversity, prevalence, and ecological roles are underestimated due to the limited scope of previous investigations. Using metabarcoding of the V4 region of the 18S rRNA gene, we characterized the eukaryotic microbiomes of the dominant crustacean zooplankton, specifically copepods, krill, amphipods, and ostracods, from the Strait of Georgia, Canada.