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

No. The fastest connection is via Kaohsiung, about 5h 47m of total flying time.

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

via Kaohsiung ≈ 5h 47m, via Beijing ≈ 5h 55m, via Osaka ≈ 6h 52m (estimated flying time, excluding layovers).

Seoul Gimpo International Airport (GMP) to Don Mueang International Airport (DMK)・3,688 km

No nonstop flights. The fastest connection is via Kaohsiung (KHH), about 5h 47m of flying time (layover not included).

None.

4 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.