Cheapest return flights from Philadelphia to Lisbon in September from $643

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

Return flights

29 Sep - 10 Oct Aer Lingus
09 Sep - 15 Sep Air Canada
27 Sep - 21 Oct TAP
26 Sep - 23 Oct Frontier Airlines
20 Sep - 01 Oct Aer Lingus
21 Sep - 01 Oct Frontier Airlines
24 Sep - 30 Sep jetBlue
22 Sep - 01 Oct American Airlines
20 Sep - 31 Oct Spirit Airlines
14 Sep - 18 Sep Spirit Airlines
20 Sep - 29 Oct Spirit Airlines
30 Sep - 25 Oct Aer Lingus
20 Sep - 28 Oct British Airways
10 Sep - 20 Sep Spirit Airlines
16 Sep - 19 Sep Frontier Airlines
07 Sep - 11 Sep Spirit Airlines
11 Sep - 23 Sep Spirit Airlines
25 Sep - 28 Sep Spirit Airlines
07 Sep - 27 Sep Spirit Airlines
07 Sep - 14 Sep Spirit Airlines

Also check the deals for one-way flights from Philadelphia to Lisbon in September.

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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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