Kos is one of the regional units of Greece. It is part of the region of South Aegean

South Aegean

The South Aegean is one of the thirteen regions of Greece. It consists of the Cyclades and Dodecanese island groups in the central and southeastern Aegean Sea.- Administration :...

. The regional unit covers the islands of Kos

Kos

Kos or Cos is a Greek island in the south Sporades group of the Dodecanese, next to the Gulf of Gökova/Cos. It measures by , and is from the coast of Bodrum, Turkey and the ancient region of Caria. Administratively the island forms a separate municipality within the Kos peripheral unit, which is...

, Nisyros

Nisyros

Nisyros is a volcanic Greek island and municipality located in the Aegean Sea. It is part of the Dodecanese group of islands, situated between the islands of Kos and Tilos. Its shape is approximately round, with a diameter of about , and an area of . Several other islets are found in the direct...

 and several smaller islands in the Aegean Sea

Aegean Sea

The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...

.

Administration

As a part of the 2011 Kallikratis government reform, the regional unit Kos was created out of part of the former Dodecanese Prefecture. It is subdivided into 2 municipalities. These are (number as in the map in the infobox):

• Kos
  Kos
  Kos or Cos is a Greek island in the south Sporades group of the Dodecanese, next to the Gulf of Gökova/Cos. It measures by , and is from the coast of Bodrum, Turkey and the ancient region of Caria. Administratively the island forms a separate municipality within the Kos peripheral unit, which is...
  
   (7)
• Nisyros
  Nisyros
  Nisyros is a volcanic Greek island and municipality located in the Aegean Sea. It is part of the Dodecanese group of islands, situated between the islands of Kos and Tilos. Its shape is approximately round, with a diameter of about , and an area of . Several other islets are found in the direct...
  
  (11)