AirHint found the following cheapest return flights from Seoul (GMP) to Ulaanbaatar (UBN) in October 2025 (see full year).

Return flights

16 Oct - 19 Oct	Air Seoul, Inc
17 Oct - 25 Oct	Air China
20 Oct - 24 Oct	Air China
21 Oct - 23 Oct	Air China
15 Oct - 19 Oct	Air China
19 Oct - 25 Oct	Air China
20 Oct - 23 Oct	Air China
29 Oct - 31 Oct	Air China
23 Oct - 25 Oct	Air China
12 Oct - 16 Oct	Air China

Also check the deals for one-way flights from Seoul to Ulaanbaatar in October.

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 Seoul to Ulaanbaatar in October from $406

Return flights