AirHint found the following cheapest return flights from Chiang Mai (CNX) to London (LGW) in December 2025 (see full year).

Return flights

17 Dec - 06 Jan	Nok Air
23 Dec - 06 Jan	Nok Air
16 Dec - 17 Jan	China Eastern
15 Dec - 30 Dec	China Eastern
19 Dec - 03 Jan	Thai VietJet Air
07 Dec - 12 Dec	Thai Lion Air
08 Dec - 15 Dec	Thai AirAsia
10 Dec - 17 Dec	Thai VietJet Air
15 Dec - 18 Dec	China Eastern
18 Dec - 04 Jan	Thai VietJet Air
22 Dec - 26 Dec	Thai AirAsia
16 Dec - 06 Jan	SWISS
25 Dec - 01 Jan	Scoot
11 Dec - 18 Dec	Scoot
19 Dec - 26 Dec	China Eastern

Also check the deals for one-way flights from Chiang Mai to London 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 Chiang Mai to London in December from 594€

Return flights