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

Return flights

28 Aug - 26 Sep	Air Canada
28 Aug - 23 Sep	Air Canada
20 Aug - 24 Aug	Alaska Airlines
28 Aug - 25 Sep	Air Canada
28 Aug - 01 Sep	Air Canada
18 Aug - 25 Aug	Air Canada
16 Aug - 13 Sep	Air Canada
20 Aug - 30 Aug	Air Canada
29 Aug - 28 Sep	Air Canada
12 Aug - 16 Aug	Air Canada
21 Aug - 28 Aug	Air Canada
13 Aug - 30 Sep	Air Canada
12 Aug - 30 Sep	Air Canada
11 Aug - 30 Sep	Air Canada
06 Aug - 13 Aug	Alaska Airlines
05 Aug - 24 Sep	Air Canada
18 Aug - 30 Aug	China Airlines
01 Aug - 08 Aug	Air Canada
01 Aug - 17 Aug	Air Canada
08 Aug - 15 Aug	Air Canada

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

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 August from $815

Return flights