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

Return flights

12 Jan - 22 Jan	Frontier Airlines
23 Jan - 26 Jan	Frontier Airlines
12 Jan - 20 Jan	Frontier Airlines
08 Jan - 15 Jan	Air Canada
11 Jan - 31 Jan	Spirit Airlines
17 Jan - 31 Jan	Frontier Airlines
14 Jan - 07 Feb	Spirit Airlines
06 Jan - 31 Jan	Spirit Airlines
29 Jan - 03 Feb	Spirit Airlines
16 Jan - 30 Jan	TAP
08 Jan - 16 Jan	TAP
08 Jan - 17 Jan	Spirit Airlines
24 Jan - 14 Feb	Spirit Airlines
25 Jan - 14 Feb	TAP

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

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 January from $481

Return flights