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

Return flights

10 Sep - 16 Sep	Thai Lion Air
27 Sep - 03 Oct	Thai Lion Air
17 Sep - 25 Sep	Thai Lion Air
30 Sep - 19 Oct	Thai Lion Air
06 Sep - 30 Sep	Thai Lion Air
17 Sep - 20 Sep	Thai Lion Air
08 Sep - 15 Sep	Thai Lion Air
12 Sep - 15 Sep	Thai Lion Air
25 Sep - 02 Oct	Thai Lion Air
08 Sep - 11 Sep	Thai AirAsia
08 Sep - 10 Sep	Thai Lion Air
24 Sep - 15 Oct	Thai AirAsia
16 Sep - 19 Sep	Thai AirAsia
08 Sep - 21 Sep	Thai AirAsia
12 Sep - 30 Oct	Thai Lion Air
08 Sep - 09 Oct	Thai AirAsia
12 Sep - 31 Oct	Thai Lion Air
08 Sep - 04 Oct	Thai AirAsia
07 Sep - 05 Oct	Thai AirAsia
08 Sep - 07 Oct	Thai Lion Air

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 $810

Return flights