AirHint found the following cheapest one-way flights from Chiang Mai (CNX) to London (LGW) in September 2025 (see full year).

One-Way flights

30 Sep	Thai AirAsia
25 Sep	Thai VietJet Air
29 Sep	Nok Air
27 Sep	Thai AirAsia
24 Sep	Nok Air
22 Sep	Thai AirAsia
19 Sep	Thai VietJet Air
21 Sep	Thai AirAsia
23 Sep	Thai Lion Air
20 Sep	Thai AirAsia

Also check the deals for return flights from Chiang Mai 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.

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Cheapest one-way flights from Chiang Mai to London in September from 236€

One-Way flights