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

Return flights

19 Sep - 29 Sep	IndiGo
25 Sep - 08 Oct	Thai Lion Air
23 Sep - 02 Oct	Air India
22 Sep - 02 Oct	Air India
05 Sep - 12 Sep	Air India
05 Sep - 08 Sep	Air China
03 Sep - 08 Sep	Air China
01 Sep - 05 Sep	China Southern
04 Sep - 08 Sep	China Southern
24 Sep - 01 Oct	IndiGo
26 Sep - 06 Oct	Air India
22 Sep - 10 Oct	Thai Airways
07 Sep - 13 Sep	Thai Airways
24 Sep - 12 Oct	Air China
21 Sep - 04 Oct	Thai Lion Air
10 Sep - 17 Sep	Thai Airways
11 Sep - 18 Sep	Thai Airways
12 Sep - 19 Sep	Thai Airways
30 Sep - 07 Oct	Thai Airways
26 Sep - 03 Oct	Air China

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

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 Seoul

Cheap car rent in Seoul

Cheapest return flights from Kathmandu to Seoul in September from 439€

Return flights