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

Return flights

23 Sep - 30 Sep	United
19 Sep - 26 Sep	Air Canada
29 Sep - 06 Oct	Iberia	direct
25 Sep - 29 Sep	Finnair
18 Sep - 25 Sep	United
09 Sep - 16 Sep	British Airways	direct
10 Sep - 17 Sep	Iberia	direct
26 Sep - 03 Oct	Iberia	direct
19 Sep - 26 Sep	British Airways	direct
25 Sep - 29 Sep	British Airways	direct
02 Sep - 09 Sep	United
19 Sep - 22 Sep	Air Canada

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 466€

Return flights