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

Return flights

03 Dec - 22 Dec	Frontier Airlines
04 Dec - 07 Dec	Turkish Airlines
10 Dec - 17 Jan	Turkish Airlines
08 Dec - 14 Dec	Turkish Airlines
29 Dec - 24 Jan	Turkish Airlines
24 Dec - 19 Jan	Air Canada
12 Dec - 22 Jan	Air Canada
05 Dec - 12 Dec	Frontier Airlines
11 Dec - 17 Jan	Turkish Airlines
14 Dec - 16 Jan	Frontier Airlines
09 Dec - 29 Dec	Alaska Airlines
10 Dec - 09 Jan	Turkish Airlines
09 Dec - 16 Dec	Turkish Airlines
12 Dec - 20 Dec	Turkish Airlines
12 Dec - 17 Jan	Turkish Airlines
10 Dec - 07 Jan	Turkish Airlines
15 Dec - 22 Jan	Turkish Airlines
24 Dec - 31 Dec	Frontier Airlines
14 Dec - 31 Dec	United
03 Dec - 22 Dec	Delta	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 861€

Return flights