Chroococcus cohaerens is a species of cyanobacteria in the family Chroococcaceae, documented from freshwater and aquatic environments. Chroococcus is a genus of small, spherical to hemispherical cyanobacterial cells that typically occur in pairs or small groups of two to four cells, surrounded by individual sheaths that are embedded within a common gelatinous matrix. The cells are dark olive-green to blue-green in color due to the presence of phycocyanin and chlorophyll a pigments. Cyanobacteria of the genus Chroococcus are common components of the periphyton and plankton of nutrient-moderate freshwater bodies in temperate regions. They are found attached to submerged substrates or floating in the water column. Chroococcus species have been documented from a wide range of geographic regions including Scandinavia, where many of the described species in this genus were originally characterized. The species has no significant economic importance and is not considered a bloom-forming taxon. Its conservation status has not been assessed by the IUCN, consistent with the general approach to prokaryotic microorganisms in conservation frameworks.