Dikaios (Greek: Δίκαιος) is a former municipality on the island of Kos, in the Dodecanese, Greece.

Since the 2011 local government reform, it is part of the municipality Kos, of which it is a municipal unit.

The seat of the municipality was in Zipari.

The municipal unit, which comprises about one-fifth of the island's territory, has a land area of 62.575 km².

This South Aegean location article is a stub.