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

Return flights

05 Dec - 21 Dec	China Airlines
05 Dec - 20 Dec	China Airlines
01 Dec - 08 Dec	China Airlines
08 Dec - 22 Dec	China Airlines
02 Dec - 16 Dec	China Airlines
01 Dec - 16 Dec	China Airlines
05 Dec - 19 Dec	China Airlines
07 Dec - 21 Dec	China Airlines
05 Dec - 10 Jan	Alaska Airlines
05 Dec - 09 Dec	China Airlines
01 Dec - 15 Dec	China Airlines
22 Dec - 15 Jan	Alaska Airlines
25 Dec - 13 Jan	China Airlines
22 Dec - 14 Jan	Alaska Airlines
10 Dec - 12 Jan	Alaska Airlines
26 Dec - 10 Jan	China Airlines
27 Dec - 10 Jan	China Airlines
12 Dec - 19 Jan	China Airlines
22 Dec - 29 Jan	China Airlines
22 Dec - 19 Jan	China Airlines

Also check the deals for one-way flights from Ontario 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 Ontario to Seoul in December from $1195

Return flights