The is no airport in Ermioni. The closest airport is located in Athens, the capital of Greece. The airport of Athens operates domestic flights from most Greek airports and also operates international flights.
There is a daily ferry connection from the port of Piraeus to Ermioni. The ferry trip lasts about 2 hours. There is also a bus to Ermioni from Kifissos KTEL Bus Station in Athens, either direct or via Nafplion.