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

Return flights

15 Sep - 22 Sep	Hainan Airlines
11 Sep - 22 Sep	China Eastern
17 Sep - 22 Sep	China Eastern
08 Sep - 29 Sep	Hainan Airlines
19 Sep - 22 Sep	Scoot
11 Sep - 13 Sep	China Eastern
10 Sep - 13 Sep	China Eastern
08 Sep - 14 Sep	Hainan Airlines
15 Sep - 21 Oct	Hainan Airlines
16 Sep - 19 Sep	Thai Lion Air
10 Sep - 15 Sep	Thai AirAsia
05 Sep - 03 Oct	China Eastern
07 Sep - 10 Oct	China Eastern
04 Sep - 04 Oct	China Eastern
09 Sep - 07 Oct	China Eastern
13 Sep - 12 Oct	China Eastern
03 Sep - 21 Oct	China Eastern
19 Sep - 14 Oct	Scoot
03 Sep - 02 Oct	China Eastern
28 Sep - 10 Oct	IndiGo

Also check the deals for one-way flights from Bangkok 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 Bangkok to London in September from 509€

Return flights