AirHint found the following cheapest one-way flights from Bangkok (BKK) to Helsinki (HEL) in September 2025 (see full year).

One-Way flights

17 Sep	Thai Lion Air
23 Sep	IndiGo
08 Sep	Thai VietJet Air
15 Sep	Hainan Airlines
10 Sep	Thai VietJet Air
06 Sep	Thai VietJet Air
22 Sep	Thai VietJet Air
19 Sep	Hainan Airlines
11 Sep	Hainan Airlines
27 Sep	IndiGo

Also check the deals for return flights from Bangkok to Helsinki 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 Bangkok to Helsinki in September from 298€

One-Way flights