Commissar is an English transliteration of the Russian комиссáр (komissar), which means 'commissary'. In English, the transliteration commissar often refers specifically to the political commissars of Soviet and Eastern-bloc armies or to the people's commissars, while administrative officers are called commissaries.

The Council of People's Commissars (CPC) (Russian: Совет народных комиссаров (СНК), romanized: Sovet narodnykh kommissarov (SNK)), commonly known as the Sovnarkom (Совнарком), were the highest executive authorities of the Russian Soviet Federative Socialist Republic (RSFSR), the Soviet Union (USSR), and the Soviet republics from 1917 to 1946.