Cheapest return flights from Philadelphia to Lisbon in September from $669

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

Return flights

24 Sep - 30 Sep TAP
01 Sep - 09 Sep Aer Lingus
11 Sep - 23 Sep TAP
15 Sep - 27 Sep TAP
17 Sep - 27 Sep TAP
10 Sep - 20 Sep TAP
01 Sep - 09 Sep American Airlines direct
26 Sep - 03 Oct United
29 Sep - 06 Oct United
20 Sep - 27 Sep United
02 Sep - 09 Sep United
08 Sep - 15 Sep United

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

Skyscanner

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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