AirHint found the following cheapest return flights from Washington (IAD) to Seoul (ICN) in May 2026 (see full year).

Return flights

21 May - 04 Jun	Porter Airlines (Canada) Ltd
06 May - 29 May	Etihad Airways
12 May - 16 Jun	Turkish Airlines
05 May - 19 Jun	Turkish Airlines
14 May - 04 Jun	Alaska Airlines
05 May - 09 May	Alaska Airlines
02 May - 09 May	Alaska Airlines
18 May - 25 May	Alaska Airlines
21 May - 25 May	Porter Airlines (Canada) Ltd
06 May - 29 May	Air Premia	direct
18 May - 25 May	Air Premia	direct
12 May - 16 Jun	Delta	direct
14 May - 04 Jun	Delta	direct
05 May - 19 Jun	Delta	direct
02 May - 09 May	Delta	direct
21 May - 04 Jun	Delta	direct
19 May - 26 May	Delta	direct
21 May - 31 May	Delta	direct
31 May - 07 Jun	Emirates

Also check the deals for one-way flights from Washington to Seoul in May.

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 Washington to Seoul in May from 943€

Return flights