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

Return flights

22 Sep - 01 Oct	Iberia	direct
23 Sep - 30 Sep	United
24 Sep - 01 Oct	United
24 Sep - 01 Oct	Iberia	direct
25 Sep - 02 Oct	Iberia	direct
26 Sep - 03 Oct	Iberia	direct
29 Sep - 06 Oct	Iberia	direct
22 Sep - 29 Sep	United
23 Sep - 30 Sep	Iberia	direct
16 Sep - 23 Sep	Iberia	direct
30 Sep - 07 Oct	Iberia	direct
09 Sep - 16 Sep	British Airways	direct
10 Sep - 17 Sep	British Airways	direct
28 Sep - 05 Oct	British Airways	direct
18 Sep - 25 Sep	United
19 Sep - 26 Sep	United
22 Sep - 29 Sep	Iberia	direct
15 Sep - 22 Sep	Iberia	direct
14 Sep - 04 Oct	British Airways
17 Sep - 11 Oct	British Airways	direct

Also check the deals for one-way flights from Philadelphia to Madrid 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 Madrid in September from 446€

Return flights