Lemnos () is one of the regional units of Greece. It is part of the region of North Aegean. The regional unit covers the islands of Lemnos, Agios Efstratios and a few smaller, uninhabited islands, in the Aegean Sea.
As a part of the 2011 Kallikratis government reform, the regional unit Lemnos was created out of part of the former Lesbos Prefecture. It is subdivided into 2 municipalities. These are (number as in the map in the infobox):
The province of Lemnos () was one of the provinces of the Lesbos Prefecture. It had the same territory as the present regional unit. It was abolished in 2006.