AirHint found the following cheapest return flights from London (LON) to Bangkok (BKK) in September 2026 (see full year).

Return flights

22 Sep - 22 Oct	Air China
01 Sep - 14 Sep	Air China
08 Sep - 21 Sep	Air China
07 Sep - 21 Sep	Air China
03 Sep - 16 Sep	Air China
04 Sep - 18 Sep	Air China
01 Sep - 11 Sep	Air China
01 Sep - 18 Sep	Air China
09 Sep - 23 Sep	Air China
01 Sep - 04 Sep	Air China
16 Sep - 23 Sep	Air China
14 Sep - 31 Oct	Air China
22 Sep - 13 Oct	Air China
23 Sep - 14 Oct	Air China
17 Sep - 16 Oct	Air China
21 Sep - 12 Oct	Air China
14 Sep - 14 Oct	Air China
11 Sep - 04 Oct	Air China
18 Sep - 04 Oct	Air China
28 Sep - 19 Oct	Air China

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

Cheap car rent in Bangkok

Cheapest return flights from London to Bangkok in September from 480€

Return flights