AirHint found the following cheapest return flights from Boston (BOS) to London (LGW) in December 2025 (see full year).

Return flights

04 Dec - 09 Dec	TAP
29 Dec - 12 Jan	Iberia
11 Dec - 15 Dec	SWISS
23 Dec - 20 Jan	Icelandair
10 Dec - 15 Dec	SWISS
10 Dec - 17 Dec	Lufthansa
16 Dec - 23 Dec	Icelandair
17 Dec - 24 Dec	Icelandair
22 Dec - 30 Dec	Icelandair
28 Dec - 02 Jan	Icelandair
14 Dec - 21 Dec	Icelandair
20 Dec - 29 Dec	Iberia
25 Dec - 01 Jan	Icelandair
26 Dec - 31 Dec	Icelandair
26 Dec - 02 Jan	Icelandair
26 Dec - 01 Jan	Icelandair
29 Dec - 03 Jan	Icelandair
19 Dec - 06 Jan	Icelandair
18 Dec - 06 Jan	Icelandair
23 Dec - 05 Jan	Icelandair

Also check the deals for one-way flights from Boston to London in December.

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 Boston to London in December from $422

Return flights