AirHint found the following cheapest return flights from Porto (OPO) to Bangkok (BKK) in September 2025 (see full year).

Return flights

04 Sep - 17 Sep	SWISS
03 Sep - 17 Sep	Lufthansa
17 Sep - 30 Sep	SWISS
09 Sep - 23 Sep	SWISS
17 Sep - 29 Sep	SWISS
24 Sep - 13 Oct	SWISS
08 Sep - 22 Sep	Lufthansa
09 Sep - 18 Sep	SWISS
03 Sep - 16 Sep	SWISS
15 Sep - 22 Sep	easyJet
20 Sep - 04 Oct	SWISS
13 Sep - 02 Oct	Austrian Airlines
15 Sep - 30 Sep	Lufthansa
01 Sep - 01 Oct	Lufthansa
26 Sep - 04 Oct	Air Europa

Also check the deals for one-way flights from Porto 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 Porto to Bangkok in September from 592€

Return flights