Chroococcus prescottii is a species of cyanobacteria in the family Chroococcaceae, named in honor of the American phycologist Gerald Weber Prescott, who made major contributions to the study of freshwater algae in North America during the twentieth century. Like other Chroococcus species, it consists of spherical cells arranged in pairs or small groups within a gelatinous sheath matrix. Cyanobacteria of this genus are common inhabitants of freshwater lakes, bogs, and other aquatic environments across temperate and boreal regions. Chroococcus prescottii has been documented from North American and European freshwater localities. The species occupies the plankton or periphyton of its host water bodies, contributing to primary production through photosynthesis. In aquatic food webs, small cyanobacteria serve as food for herbivorous zooplankton such as cladocerans and copepods, linking primary production to higher trophic levels. The taxonomy of Chroococcus has been complicated by the variable expression of morphological characters under differing environmental conditions and by the recognition through molecular analysis that the genus as traditionally defined is polyphyletic. Chroococcus prescottii has not been assessed by the IUCN.