AirHint found the following cheapest return flights from Washington (IAD) to Seoul (ICN) in December 2025 (see full year).

Return flights

13 Dec - 21 Dec	Air Canada
12 Dec - 21 Dec	Air Canada
26 Dec - 23 Jan	Air Canada
02 Dec - 23 Dec	Turkish Airlines
11 Dec - 21 Dec	Turkish Airlines
20 Dec - 18 Jan	Air Canada
17 Dec - 17 Jan	Air Canada
24 Dec - 03 Jan	Alaska Airlines
24 Dec - 02 Jan	Air Canada
24 Dec - 09 Jan	Hawaiian Airlines
19 Dec - 06 Jan	Air Canada
21 Dec - 02 Jan	Air Canada
20 Dec - 10 Jan	Air Canada
24 Dec - 09 Jan	Delta	direct
12 Dec - 21 Dec	Korean Air	direct
02 Dec - 23 Dec	Korean Air	direct
11 Dec - 21 Dec	Korean Air	direct
13 Dec - 21 Dec	Korean Air	direct

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

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 December from $1064

Return flights