Data characterize zooplankton in Shelbyville Reservoir, Illinois, United States of America. Zooplankton were sampled with a conical zooplankton net (0.5m diameter mouth) when water was deeper than 2 m and by grab sample when water was shallower. Zooplankton samples were concentrated and subsampled with a Hensen-Stempel pipette following protocols described in Detmer et al. (2019). Zooplankton were identified to the lowest feasible taxonomic unit according to Pennak (1989) and Thorp and Covich (2001) and were...