Polkovnik (Russian: полковник, Polish: pułkownik, Ukrainian: полковник, Czech: plukovník; literally "regimentary") is often a military rank in Slavic countries which corresponds to a colonel in English-speaking states. However, in the Ukraine, polkovnyk was an administrative rank similar to a governor. Usually this word is translated as colonel, however the transliteration is also in common usage, for the sake of the historical and social context.

The exact name of this rank maintains a variety of spellings in different languages, but all descendant from the Old Slavonic word polk, and include the following:

Polkovnik began as a commander of a distinct group of troops, Old Slavonic polk (полк), arranged for a particular battle.

In late 17th century, polkovnik became the position of a regimental commander of the streltsy; this position also made it into New Regiments of the streltsy and later into the new army of Peter the Great. The rank was legalized by Table of Ranks that placed it in the 6th grade as the second-top field officer, right under the brigadier. A promotion to the rank of polkovnik gave a privilege of hereditary nobility.