AirHint found the following cheapest return flights from London (LHR) to Seoul (GMP) in September 2025 (see full year).

Return flights

07 Sep - 10 Sep	Air China
02 Sep - 05 Sep	Air China
02 Sep - 09 Sep	Air China
22 Sep - 15 Oct	Air China
22 Sep - 14 Oct	Air China
16 Sep - 11 Oct	Air China
02 Sep - 08 Sep	Air China
09 Sep - 10 Oct	China Southern
24 Sep - 22 Oct	China Southern
18 Sep - 18 Oct	China Southern
08 Sep - 13 Oct	China Southern
03 Sep - 15 Oct	China Southern
18 Sep - 11 Oct	China Southern
23 Sep - 11 Oct	China Southern
02 Sep - 11 Sep	Air China
08 Sep - 30 Sep	Air China
17 Sep - 29 Sep	Air China
22 Sep - 29 Sep	Air China
02 Sep - 29 Sep	Air China
21 Sep - 29 Sep	Air China

Also check the deals for one-way flights from London 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 London to Seoul in September from $537

Return flights