Rethymnon, also Rethimno, is a city of little more than 30,000 people (near 40,000 for the municipal unit) in Greece, the capital of Rethymno regional unit on the island of Crete, a former Latin Catholic bishopric as Retimo and former Latin titular see.

Rethymno was originally built during the Minoan civilization (ancient Rhithymna and Arsinoe). The city was prominent enough to mint its own coins and maintain urban growth. One of these coins is today depicted as the crest of the town: two dolphins in a circle.