The title of one of the 9 Archons in the Athenian polis, and the second most important of them. The meaning of Polemarchos is 'Master of War'

The Archon Plemarchos presided over all matters that were related to the Military of Athens, and matters of public disorders. As a result of these he was also responsible to all the foreigners in the polis (originally for a foreigner to live in Athens he needed a citizen sponsor, but gradually the Archon Polemarchos became the sponsor for all foreigners in the polis), and for them he filled all the roles that were filled by the Archon Eponymos for Athenian citizens.

As the importance of the Archontes (plural from Archon) dwindled the Archon Polemarchos lost some of his responsibilities to the Archon Eponymos, but mainly to the Strategoi, and was left only with the role of presiding over foreigners.