Chroococcus varius is a species of cyanobacteria in the family Chroococcaceae. The specific epithet varius, meaning variable or diverse, may reflect the morphological variability of this species across different environmental conditions, a characteristic shared by many cyanobacteria of the genus. Chroococcus species can show considerable plasticity in cell size, sheath color, and colony arrangement depending on growth conditions, which has historically complicated species-level identification. Chroococcus varius has been documented from freshwater and aquatic habitats, contributing to the diverse microflora of lakes, ponds, and slow-moving waters. Like other members of the genus, it consists of spherical cells in pairs or small groups enclosed within a gelatinous matrix. The cells perform oxygenic photosynthesis and contribute to primary production in their aquatic ecosystems. Cyanobacteria of the Chroococcaceae family are among the most ecologically generalist cyanobacterial groups, occupying habitats from polar regions to tropical freshwaters. Chroococcus varius has been recorded from European freshwater localities. The species is not assessed by the IUCN, reflecting the limited application of conservation frameworks to prokaryotic microorganisms.