Seattle (SEA) to Seoul (SEL): 5,203 miles (8,373 km) great-circle, about 10h 55m nonstop by our estimate. Cheapest fare observed: $1127 round-trip on Qatar, with 1 stop, departing May 11, 2026.
$1127 round-trip, Qatar QR720, departing 2026-05-11 at 17:05, returning 2026-05-22. The recorded itinerary left on a Monday, returning on a Friday 11 nights later; the fare was observed 16 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $1127, it ranked 24th of the 30 round-trip fares we recorded from SEA (median $591). That is 21.7 cents per great-circle mile (round-trip price over one-way distance), above the SEA median of 19.2 cents across 30 round-trip routes.
Routes from SEA of similar length: Moscow (5,195 mi) at $1513 and Milan (5,356 mi) at $972.
Qatar had the cheapest fare on 3 of 30 SEA routes. It is the 9th longest of the 30 routes we track from SEA.
Of 24 departure airports with a fare to Seoul, Seattle (SEA) ranked 22nd at $1127. 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 America/Los_Angeles, Asia/Seoul; flight time is our estimate.