AirHint found the following cheapest one-way flights from Porto (OPO) to Bilbao (BIO) in September 2025 (see full year).

One-Way flights

25 Sep	Volotea	direct
19 Sep	Vueling Airlines	direct
07 Sep	Volotea	direct
30 Sep	Vueling Airlines
09 Sep	Vueling Airlines	direct
23 Sep	Vueling Airlines
30 Sep	Vueling Airlines	direct
10 Sep	Ryanair
17 Sep	Vueling Airlines
13 Sep	Vueling Airlines	direct

Also check the deals for return flights from Porto to Bilbao 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 Porto to Bilbao in September from 22€

One-Way flights