Ferries from Ios to Kythnos can peak at up to undefined daily sailings, Sailing frequency typically peaks in the summer months, with approximately undefined departures offered each week. While schedules may be reduced from Ios to Kythnos in other seasons, ferry services are often still available.

Ferry travel from Ios to Kythnos on average typically takes -. The earliest ferry usually leaves from Ios at -, arriving to Kythnos at - The latest ferry departs at - and arrives at -.