Cheapest return flights from Philadelphia to Lisbon in September from $631

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

Return flights

22 Sep - 01 Oct TAP
19 Sep - 24 Sep Spirit Airlines
23 Sep - 05 Oct TAP
03 Sep - 17 Sep TAP
11 Sep - 17 Sep TAP
17 Sep - 23 Sep TAP
11 Sep - 23 Sep TAP
10 Sep - 20 Sep jetBlue
22 Sep - 29 Sep United
25 Sep - 02 Oct United
28 Sep - 05 Oct United
19 Sep - 26 Sep United
10 Sep - 17 Sep United
16 Sep - 23 Sep United
22 Sep - 01 Oct Finnair direct

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.

Book a cheap hotel in Lisbon

Cheap car rent in Lisbon

Feel free to contact us with any feedback or request another flight research.