AirHint found the following cheapest return flights from Philadelphia (PHL) to London (LGW) in May 2026 (see full year).

Return flights

01 May - 03 May	Air Canada
01 May - 16 May	Frontier Airlines
25 May - 01 Jun	Aer Lingus
20 May - 26 May	Air Canada
05 May - 12 May	British Airways
08 May - 25 May	Frontier Airlines
23 May - 01 Jun	Spirit Airlines
09 May - 16 May	Frontier Airlines
02 May - 05 May	Spirit Airlines
13 May - 25 May	Spirit Airlines
13 May - 18 May	TAP
27 May - 09 Jun	TAP
17 May - 24 May	TAP
22 May - 09 Jun	jetBlue
26 May - 09 Jun	TAP
29 May - 15 Jun	Aer Lingus
22 May - 07 Jun	TAP

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

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 London in May from $639

Return flights