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

Return flights

19 Apr - 27 Apr	Air Canada
19 Apr - 29 Apr	Air Canada
07 Apr - 21 Apr	Air Canada
29 Apr - 13 May	Air Canada
21 Apr - 21 May	Air Canada
13 Apr - 23 Apr	Air Canada
15 Apr - 22 Apr	Air Canada
19 Apr - 03 May	Air Canada
12 Apr - 22 Apr	Air Canada
08 Apr - 18 Apr	Air Canada
08 Apr - 18 Apr	Korean Air	direct
13 Apr - 23 Apr	Korean Air	direct
15 Apr - 22 Apr	Korean Air	direct
19 Apr - 03 May	Korean Air	direct
20 Apr - 04 May	Korean Air	direct
21 Apr - 21 May	Asiana Airlines	direct
29 Apr - 13 May	Delta	direct

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

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 April from $789

Return flights