Ermionida (Greek: Ερμιονίδα) is a municipality in the Argolis regional unit, Peloponnese, Greece. The seat of the municipality is the town Kranidi.
The municipality Ermionida was formed at the 2011 local government reform by the merger of the following 2 former municipalities, that became municipal units:
The province of Ermionida (Greek: Επαρχία Ερμιονίδας) was one of the three provinces of Argolis Prefecture. It was abolished in 2006. Its territory covered the territory of the present Ermionida municipality.