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

Return flights

23 Sep - 01 Oct	Transavia France
30 Sep - 02 Oct	Ryanair
29 Sep - 01 Oct	Wizz Air Malta
29 Sep - 02 Oct	easyJet
16 Sep - 18 Sep	Transavia France
19 Sep - 25 Sep	Ryanair
30 Sep - 07 Oct	easyJet
23 Sep - 02 Oct	Transavia France
30 Sep - 03 Oct	Ryanair
18 Sep - 25 Sep	Ryanair
22 Sep - 30 Sep	Wizz Air Malta
25 Sep - 02 Oct	Ryanair
23 Sep - 29 Sep	easyJet
17 Sep - 29 Sep	easyJet
28 Sep - 02 Oct	Ryanair
08 Sep - 18 Sep	Vueling Airlines
29 Sep - 06 Oct	easyJet
16 Sep - 25 Sep	Ryanair
19 Sep - 23 Sep	Ryanair
23 Sep - 26 Sep	Transavia France

Also check the deals for one-way flights from Porto to Athens 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 return flights from Porto to Athens in September from $176

Return flights