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

Return flights

25 Aug - 19 Sep	Air Canada
24 Aug - 13 Sep	Air Canada
22 Aug - 23 Sep	Air Canada
14 Aug - 13 Sep	WestJet
13 Aug - 24 Aug	Hawaiian Airlines
20 Aug - 24 Aug	Hawaiian Airlines
23 Aug - 01 Sep	WestJet
20 Aug - 27 Aug	WestJet
05 Aug - 07 Sep	WestJet
18 Aug - 25 Aug	WestJet
22 Aug - 31 Aug	WestJet
17 Aug - 24 Aug	Hawaiian Airlines
18 Aug - 01 Sep	WestJet
09 Aug - 20 Aug	WestJet
16 Aug - 23 Aug	WestJet
10 Aug - 19 Aug	China Airlines
21 Aug - 19 Sep	WestJet
20 Aug - 23 Aug	Philippine Airlines
25 Aug - 19 Sep	Asiana Airlines	direct
24 Aug - 13 Sep	Delta	direct

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.

Book a cheap hotel in Seoul

Cheap car rent in Seoul

Cheapest return flights from Seattle to Seoul in August from 740€

Return flights