Chroococcus minutus is a cyanobacterium in the family Chroococcaceae, recognized as one of the smaller species in the genus. It is distributed in freshwater habitats across temperate regions, including Scandinavia and northern Europe, where it has been documented in taxonomic surveys of freshwater algae and cyanobacteria. Chroococcus species in general are characterized by their simple morphology — spherical or hemispherical cells, binary fission, and organization into pairs or tetrads within gelatinous sheaths. Chroococcus minutus occurs in the plankton and periphyton of lakes, ponds, and slowly flowing waters with low to moderate nutrient levels. Cyanobacteria of this type play roles in primary production and, in certain metabolically active strains, may contribute to nitrogen fixation in nitrogen-limited aquatic systems. The taxonomy of small-celled Chroococcus species remains challenging, with morphological overlap between species and significant variation in cell size related to environmental conditions and growth stage. Recent molecular studies have revealed that morphologically defined genera such as Chroococcus represent multiple phylogenetic lineages, indicating likely future taxonomic rearrangements. The species is not assessed by the IUCN.