Are there nonstop flights from Rishiri (RIS) to Seoul (ICN)?

No. The fastest connection is via Sapporo, about 3h of total flying time.

What is the fastest connection from Rishiri (RIS) to Seoul (ICN)?

via Sapporo ≈ 3h (estimated flying time, excluding layovers).

Rishiri Airport (RIS) to Incheon International Airport (ICN)・1,499 km

No nonstop flights. The fastest connection is via Sapporo (CTS), about 3h of flying time (layover not included).

None.

1 one-stop options, sorted by estimated flying time. Tap one to see the airlines on each leg and booking links.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.