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

Return flights

24 Sep - 30 Sep	T'way Air
10 Sep - 15 Sep	China Eastern
10 Sep - 17 Sep	China Eastern
08 Sep - 16 Sep	China Eastern
08 Sep - 14 Sep	China Eastern
18 Sep - 27 Sep	China Eastern
18 Sep - 29 Sep	China Eastern
22 Sep - 30 Sep	Emirates
22 Sep - 25 Sep	Emirates
22 Sep - 29 Sep	Emirates
24 Sep - 02 Oct	Emirates
24 Sep - 05 Oct	Emirates
23 Sep - 01 Oct	Emirates
23 Sep - 03 Oct	Emirates
24 Sep - 16 Oct	Emirates
24 Sep - 15 Oct	Emirates
23 Sep - 23 Oct	Emirates
21 Sep - 26 Oct	T'way Air
24 Sep - 14 Oct	Emirates
12 Sep - 15 Oct	Jin Air

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

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Cheapest return flights from Seoul to London in September from $687

Return flights