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

Return flights

17 Dec - 22 Dec	Air China
16 Dec - 21 Dec	Air China
07 Dec - 21 Dec	Air China
18 Dec - 22 Dec	Air China
11 Dec - 15 Dec	Air China
07 Dec - 14 Dec	Air China
30 Dec - 04 Jan	Air China
31 Dec - 04 Jan	Air China
12 Dec - 18 Dec	Air China
16 Dec - 22 Dec	Air China
30 Dec - 10 Jan	Air China
10 Dec - 13 Dec	Air China
09 Dec - 13 Dec	Air China
17 Dec - 08 Jan	Air China
30 Dec - 05 Jan	Air China
31 Dec - 03 Jan	Air China
29 Dec - 06 Jan	Air China
29 Dec - 09 Jan	Air China
29 Dec - 04 Jan	Air China
16 Dec - 06 Jan	Air China

Also check the deals for one-way 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.

Book a cheap hotel in Ulaanbaatar

Cheap car rent in Ulaanbaatar

Cheapest return flights from Seoul to Ulaanbaatar in December from 206€

Return flights