Cheapest return flights from Philadelphia to London in September from 689€

Best time to book flights for Philadelphia (PHL) to London (LHR) flights at AirHint

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

Return flights

24 Sep - 01 Oct Finnair
24 Sep - 01 Oct Finnair direct
09 Sep - 19 Sep United
20 Sep - 27 Sep United
12 Sep - 23 Sep Finnair
05 Sep - 25 Sep Finnair
05 Sep - 26 Sep Finnair
12 Sep - 23 Sep Finnair direct
05 Sep - 25 Sep Finnair direct
05 Sep - 26 Sep Finnair direct
12 Sep - 15 Sep Finnair
05 Sep - 09 Sep Finnair

Also check the deals for one-way flights from Philadelphia to London 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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