Sifnos to Santorini links two very different sides of the Cyclades: the quiet, food-loving western island of pottery villages and footpaths, and the famous volcanic caldera in the south. Plenty of travellers use it to finish a western islands trip on Santorini, which has an airport and plenty of connections onward.
The crossing is longer than a glance at the map suggests. Neither company runs a straight line: both boats stop at other islands on the way, and the itinerary changes with the season. In spring and autumn the trip can take under three hours, but on our summer sample day, 12 August 2026, the Seajets boat needed 6 hr 5 min and the Fast Ferries ship 6 hr 50 min. Always look at the duration of your particular sailing before you plan the evening.
The two companies differ hugely on price. Fast Ferries runs a conventional ship with fares from €12.50, while Seajets starts at €93.70 and was listed higher in some months. In summer, when both take around six hours, the cheaper ship can make more sense; in the shoulder season, the high-speed boat can save a few hours.
Fast Ferries sails in every month, 3 to 6 days a week; Seajets joins from March to November, reaching a daily service in September and October. Check which days run in your week, and arrange your transfer from Athinios, Santorini's busy main port, before you set off.
