By ferry from the port of Piraeus. The trip lasts about 3 hours. For more information: 210 4226600.
From the port of Lavrio the trip lasts about 2 hours. For more information: 22920 25249.
Kythnos is connected in daily routes with Serifos, Sifnos, Milos and Kimolos. Twice a week there is a ferry to Santorini, Sikino and Folegandro. Three times a week there is a route to Kea.