The 74 regional units of Greece are the country's third-level administrative units (counting decentralized administrations as first-level). They are subdivisions of the country's 13 regions, and are further divided into municipalities.
They were introduced as part of the Kallikratis administrative reform on 1 January 2011 and are comparable in area and, on the mainland, coterminous with the "pre-Kallikratis" prefectures of Greece.