Commissar (комисса́р) was an official title used in post-revolutionary Russia and the Soviet Union. The usage of the title has been associated with a number of administrative and military functions in Bolshevik government. During the Russian Civil War, the White Army widely used the collective term bolsheviks and commissars for their opponents.

There are two well established titles: People's Commissar (government) and political commissar (military).

See Commissar for the movie.