Cohort or cohortes means ‘’’A definite group of people’’’, derived from the assimilated form of com (with) plus chorus (act together) from PIE verb *gher- (to grasp, to enclose). It may refer to:

• Cohort (military unit), the basic tactical unit of a Roman legion
• Cohort (educational group), a group of students working together through the same academic curriculum

• Cohort (statistics), a group of subjects with a common defining characteristic, for example age group
• Cohort (floating point), a set of different encodings of the same numerical value
• Cohort (taxonomy), in biology, one of the taxonomic ranks
• Cohort study, a form of longitudinal study used in medicine and social science
• Cohort analysis, a subset of behavioral analytics that takes the data from a given data set
• Generational cohort, an aggregation of individuals who experience the same event within the same time interval

• Cohort Studios, a video game development company
• "Cohort", a disc golf putter by Infinite Discs

• Cohortes urbanae, the riot police of Ancient Rome, also pressed into use as a military unit
• Cohortes vigilum, the firefighters and police of Ancient Rome