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

Return flights

05 Dec - 13 Dec	ITA Airways
09 Dec - 17 Dec	ITA Airways
05 Dec - 20 Dec	ITA Airways
04 Dec - 12 Dec	ITA Airways
05 Dec - 12 Dec	ITA Airways
10 Dec - 17 Dec	ITA Airways
11 Dec - 18 Dec	ITA Airways
11 Dec - 19 Dec	ITA Airways
12 Dec - 20 Dec	ITA Airways
12 Dec - 19 Dec	ITA Airways
01 Dec - 27 Jan	ITA Airways
02 Dec - 27 Jan	SWISS
09 Dec - 21 Jan	KLM
02 Dec - 26 Jan	SWISS
02 Dec - 28 Jan	SWISS
02 Dec - 29 Jan	SWISS
01 Dec - 20 Jan	SWISS
10 Dec - 21 Jan	KLM
09 Dec - 22 Jan	KLM
01 Dec - 29 Jan	SWISS

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

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 London to Bangkok in December from $712

Return flights