AirHint found the following cheapest return flights from Seattle (SEA) to Seoul (ICN) in December 2025 (see full year).

Return flights

02 Dec - 27 Dec	Air Canada
02 Dec - 27 Dec	Asiana Airlines	direct
20 Dec - 27 Dec	Air Canada
13 Dec - 03 Jan	Asiana Airlines	direct
15 Dec - 10 Jan	Delta
15 Dec - 10 Jan	Asiana Airlines	direct
20 Dec - 27 Dec	Asiana Airlines	direct
21 Dec - 03 Jan	Turkish Airlines
21 Dec - 03 Jan	Asiana Airlines	direct

Also check the deals for one-way flights from Seattle to Seoul in December.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in Seoul

Cheap car rent in Seoul

Cheapest return flights from Seattle to Seoul in December from 741€

Return flights