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

Return flights

03 Dec - 14 Dec	SriLankan Airlines
27 Dec - 03 Jan	Air China
03 Dec - 09 Dec	Air China
01 Dec - 31 Dec	Air China
21 Dec - 30 Dec	Air China
03 Dec - 14 Jan	Air China
19 Dec - 27 Dec	Air China
15 Dec - 31 Jan	Air China
20 Dec - 26 Dec	Air India
20 Dec - 27 Dec	Air India
30 Dec - 03 Jan	Air India
25 Dec - 03 Jan	Air India
06 Dec - 10 Dec	Thai Airways
22 Dec - 26 Dec	Thai Airways
02 Dec - 17 Dec	Thai Airways
23 Dec - 11 Jan	Thai Airways
23 Dec - 01 Jan	Thai Airways
30 Dec - 06 Jan	Thai Airways
24 Dec - 11 Jan	Thai Airways
23 Dec - 10 Jan	Thai Airways

Also check the deals for one-way flights from Seoul to Kathmandu 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 Kathmandu

Cheap car rent in Kathmandu

Cheapest return flights from Seoul to Kathmandu in December from $341

Return flights