Are there nonstop flights from Seoul (ICN) to Irkutsk (IKT)?

No. The fastest connection is via Ulaanbaatar, about 3h 56m of total flying time.

What is the fastest connection from Seoul (ICN) to Irkutsk (IKT)?

via Ulaanbaatar ≈ 3h 56m, via Beijing ≈ 4h, via Beijing ≈ 4h 3m (estimated flying time, excluding layovers).

from 18,500 ANA miles (economy, one way, based on the published award charts).

Incheon International Airport (ICN) to Irkutsk International Airport (IKT)・2,375 km

No nonstop flights. The fastest connection is via Ulaanbaatar (UBN), about 3h 56m of flying time (layover not included).

With milesANA 18,500 miles+ (via PEK)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

5 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.