Ataman was a title of Cossack and haidamak leaders of various kinds. In the Russian Empire, the term was the official title of the supreme military commanders of the Cossack armies. The Ukrainian version of the same word is hetman. Otaman in Ukrainian Cossack forces was a position of a lower rank.

The Cossacks are a predominantly East Slavic Orthodox Christian people originating in the Pontic–Caspian steppe of eastern Ukraine and southern Russia. Historically, they were a semi-nomadic and semi-militarized people, who, while under the nominal suzerainty of various Eastern European states at the time, were allowed a great degree of self-governance in exchange for military service. Although numerous linguistic and religious groups came together to form the Cossacks, most of them coalesced and became East Slavic-speaking Orthodox Christians.