Symi can only be reached by sea. It is connected by ferry to the port of Piraeus (16.5 hours) and to almost all Dodecanese islands: Rhodes (about 1 hour), Kos (1.5 hours), Kalymnos (2 hours), Leros (3 hours), and Patmos (4 hours). Most ferries make stops at major islands along the route.
The main ferry companies are Dodekanisos Seaways, ANES Lines, and Blue Star Ferries. For booking, refer to directferries.com.
Symi does not have an airport. The fastest way to reach it is to fly to Rhodes (connected to Athens and many European cities) and take the short ferry crossing (about 1 hour).
Connections are more frequent during the summer season; always check availability if travelling in other periods.