Siren is a boss in Final Fantasy V. She deceives the party into letting their guard down, by impersonating Bartz's mother, Stella Klauser, and King Tycoon, but her attempt to ensnare Galuf by impersonating Krile fails when Galuf cannot remember who Krile is due to his amnesia. Galuf gets the other party members to snap out of their trances, and the Siren takes a more direct approach to taking care of the party.

In the Advance version, Siren can be fought in the Cloister of the Dead section of the Sealed Temple.