Bangkok (DMK) to Seoul (SEL): 2,273 miles (3,658 km) great-circle, about 5h 05m nonstop by our estimate. Cheapest fare observed: $316 round-trip on Thai Lion Air, nonstop, departing April 28, 2026.
$316 round-trip, Thai Lion Air SL352, departing 2026-04-28 at 03:15, returning 2026-05-03. The recorded itinerary left on a Tuesday, returning on a Sunday 5 nights later; the fare was observed 3 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $316, it ranked 15th of the 30 round-trip fares we recorded from DMK (median $322). That is 13.9 cents per great-circle mile (round-trip price over one-way distance), below the DMK median of 25.1 cents across 30 round-trip routes.
Routes from DMK of similar length: Almaty (2,467 mi) at $498 and Beijing (2,051 mi) at $641.
Thai Lion Air had the cheapest fare on 5 of 30 DMK routes. It is the 13th longest of the 30 routes we track from DMK.
Of 24 departure airports with a fare to Seoul, Bangkok (DMK) ranked 14th at $316. Lowest: $142 from Osaka (KIX); highest: $1288 from Portland (PDX); 10 nonstop. Cheapest-fare airlines (routes): Jetstar (2), Peach Aviation (2), airline 9G (1), airline WE (1), Alaska Airlines (1) and Asiana (1), plus 16 more.
That depends on your passport and trip, so check the official source for South Korea: Republic of Korea: K-ETA. Connecting elsewhere? Check that country's transit rules too.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones Asia/Bangkok, Asia/Seoul; flight time is our estimate.