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

Return flights

30 Sep - 12 Oct	Air India
08 Sep - 22 Sep	Hainan Airlines
08 Sep - 15 Sep	Hainan Airlines
10 Sep - 19 Sep	Thai Lion Air
12 Sep - 29 Sep	Thai Lion Air
12 Sep - 14 Sep	Thai Lion Air
05 Sep - 17 Sep	Hainan Airlines
08 Sep - 25 Sep	Hainan Airlines
05 Sep - 15 Sep	Hainan Airlines
13 Sep - 19 Sep	Gulf Air
28 Sep - 19 Oct	Air Arabia
10 Sep - 16 Sep	Air Arabia
05 Sep - 31 Oct	Hainan Airlines
12 Sep - 13 Oct	Thai Lion Air
21 Sep - 05 Oct	AirAsia
25 Sep - 20 Oct	Gulf Air
26 Sep - 02 Oct	Thai AirAsia
27 Sep - 20 Oct	Gulf Air
23 Sep - 07 Oct	Saudia
20 Sep - 07 Oct	AirAsia

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.

Book a cheap hotel in London

Cheap car rent in London

Cheapest return flights from Bangkok to London in September from 511€

Return flights