Zemplín is the name of an informal region located in eastern Slovakia. It includes Slovak part of the former Zemplén county, often including the Slovak part of the Ung county (Slovak: Užská župa/Užský komitát).
Zemplín region stretches from the Carpathian Mountains in the north to the lowest point in Slovakia at 94 metres AMSL. The region is situated in the easternmost part of Slovakia (except for the region between Vihorlatské vrchy and the Latorica river, if the former territory of Ung county isn't included). Rivers in the region include: Bodrog, Laborec, Latorica, Uh, Ondava and a very small part of the Tisza river
Zemplín is no longer an administrative region, but is divided between two of the 21 official tourism regions, Lower Zemplín and Upper Zemplín. Administratively, the region is divided between Košice Region, which includes Trebišov and the western part of Michalovce District (if Ung county is included, eastern part of Michalovce and whole Sobrance District also belong to Zemplín), and Prešov Region, fully including Humenné, Snina and Medzilaborce districts and from bigger part including Vranov nad Topľou and Stropkov districts. Major towns include Michalovce, Trebišov and Humenné.