Ferries depart for Alonissos from Volos, Agios Konstantinos and from the port of Mantoudi in Evia . The trip lasts approximately 4 hours. During summer, there are some extra ferry routes to Alonissos from Kymi in Evia. Notice that there are no direct ferry routes from Athens to Alonissos.
In case you are traveling from Athens, you need to reach Volos or Evia by KTEL bus and then you can take the ferry that will transfer you to your destination!
Alonissos is also connected by ferry with Skiathos.

There is no airport on the small island of Alonissos. The closest one is located in Skiathos.
Skiathos International Airport "Alexandros Papadiamantis" receives flights from Athens International Airport all year round. The flight time from Athens to Skiathos is about 30 minutes. The airport also receives some seasonal flights from different places around Europe.
Upon your arrival, it is a good idea to take a taxi for your transfer, since the airport is located about 5 km away from the city center of Skiathos. There are always many taxis at the airport's entrance.
Then, you can take a ferry to Alonissos. The trip from Skiathos to Alonissos lasts two hours.