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

Return flights

28 Sep - 08 Oct	British Airways
29 Sep - 07 Oct	Delta
21 Sep - 11 Oct	British Airways
30 Sep - 10 Oct	United
30 Sep - 11 Oct	Frontier Airlines
19 Sep - 26 Sep	Frontier Airlines
18 Sep - 11 Oct	Frontier Airlines
27 Sep - 18 Oct	United
16 Sep - 20 Sep	Frontier Airlines
19 Sep - 03 Oct	Frontier Airlines
16 Sep - 19 Sep	Frontier Airlines
21 Sep - 11 Oct	Iberia	direct
30 Sep - 10 Oct	Finnair	direct
19 Sep - 26 Sep	Iberia	direct
16 Sep - 19 Sep	British Airways	direct
16 Sep - 20 Sep	British Airways	direct

Also check the deals for one-way flights from Philadelphia 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 Philadelphia to Athens in September from 483€

Return flights