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

Return flights

11 Dec - 14 Dec	Jin Air	direct
11 Dec - 17 Dec	Jin Air	direct
11 Dec - 12 Dec	Jin Air	direct
11 Dec - 13 Dec	Jin Air	direct
08 Dec - 11 Dec	Thai AirAsia
11 Dec - 19 Dec	Jin Air
01 Dec - 06 Dec	Jin Air
17 Dec - 22 Dec	Air China
01 Dec - 08 Dec	Air China
15 Dec - 06 Jan	Thai AirAsia
14 Dec - 17 Dec	Thai AirAsia
16 Dec - 18 Jan	Thai AirAsia
19 Dec - 16 Jan	Thai AirAsia
12 Dec - 08 Jan	Thai AirAsia
19 Dec - 10 Jan	Thai AirAsia
19 Dec - 08 Jan	Thai AirAsia
25 Dec - 05 Jan	Thai AirAsia
26 Dec - 13 Jan	Jin Air
23 Dec - 13 Jan	Jin Air
26 Dec - 12 Jan	Jin Air

Also check the deals for one-way flights from Chiang Mai 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 Chiang Mai to Seoul in December from $356

Return flights