Are there nonstop flights from Seoul (GMP) to Bangkok (BKK)?

No. The fastest connection is via Busan, about 5h 44m of total flying time.

What is the fastest connection from Seoul (GMP) to Bangkok (BKK)?

via Busan ≈ 5h 44m, via Kaohsiung ≈ 5h 47m, via Beijing ≈ 5h 56m (estimated flying time, excluding layovers).

from 18,500 ANA miles, from 23,000 JAL miles (economy, one way, based on the published award charts).

Seoul Gimpo International Airport (GMP) to Suvarnabhumi Airport (BKK)・3,698 km

No nonstop flights. The fastest connection is via Busan (PUS), about 5h 44m of flying time (layover not included).

With milesANA 18,500 miles+ (via PEK)JAL 23,000 miles+ (via PUS)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

7 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.