AirHint found the following cheapest return flights from Seattle (SEA) to Seoul (ICN) in January 2026 (see full year).

Return flights

10 Jan - 24 Jan	Frontier Airlines
04 Jan - 31 Jan	Frontier Airlines
19 Jan - 27 Jan	Air Canada
31 Jan - 26 Feb	Hawaiian Airlines
12 Jan - 16 Feb	Asiana Airlines	direct
29 Jan - 08 Feb	Air Canada
19 Jan - 27 Jan	Korean Air	direct
22 Jan - 11 Feb	Air Canada
30 Jan - 06 Feb	Korean Air	direct
10 Jan - 24 Jan	Delta	direct
31 Jan - 26 Feb	Delta	direct
19 Jan - 25 Jan	Delta	direct
04 Jan - 31 Jan	Delta	direct
29 Jan - 08 Feb	Delta	direct
22 Jan - 11 Feb	Delta	direct
23 Jan - 31 Jan	Air Canada
02 Jan - 09 Jan	Korean Air	direct

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

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.

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Cheapest return flights from Seattle to Seoul in January from 666€

Return flights