Chief Archon is a Cardassian judiciary position and the head of the Cardassian Supreme Tribunal.
When Rokan Du'Lam was Chief Archon, Du'Lam was known for ensuring that court sentences were stern. (DS9 novel: A Stitch in Time)
Makbar was Chief Archon in 2370 and 2382. (DS9 episode: "Tribunal", ST - Typhon Pact novel: Raise the Dawn)
Teretis Geyl was Chief Archon from 2371 to 2373, during the period of civilian government under Meya Rejal. As Chief Archon, Geyl attempted to resist the Dominion takeover of Cardassia, but was later executed by the Jem'Hadar. (DS9 novel: The Never-Ending Sacrifice)