Mases (Ancient Greek: Μάσης, ἡ Μάσητος) was a city in the district Hermionis, on the Argolic peninsula, in ancient Argolis. It is mentioned by Homer as part of Diomedes's kingdom in the Catalogue of Ships in the Iliad, along with Aegina. In the time of Pausanias, it was used as a harbour by Hermione.
Its site is tentatively located near the modern Koilada, northeast of Kranidi.
This article incorporates text from a publication now in the public domain: Smith, William, ed. (1854–1857). "Mases". Dictionary of Greek and Roman Geography. London: John Murray.
37°25′04″N 23°08′32″E / 37.417868°N 23.142191°E