AirHint found the following cheapest one-way flights from Seoul (ICN) to Ulaanbaatar (UBN) in December 2025 (see full year).

One-Way flights

02 Dec	Jeju Air	direct
16 Dec	Jeju Air	direct
18 Dec	Jeju Air	direct
21 Dec	Jeju Air	direct
23 Dec	Jeju Air	direct
07 Dec	Jeju Air	direct
17 Dec	Air China
11 Dec	Air China
11 Dec	Jeju Air	direct
17 Dec	Aero Mongolia	direct

Also check the deals for return flights from Seoul to Ulaanbaatar 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 one-way flights from Seoul to Ulaanbaatar in December from 75€

One-Way flights