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

Return flights

06 Dec - 12 Dec	Icelandair
05 Dec - 11 Dec	Icelandair
05 Dec - 10 Dec	Icelandair
03 Dec - 07 Dec	Icelandair
03 Dec - 10 Dec	Icelandair
12 Dec - 14 Dec	Icelandair
05 Dec - 07 Dec	Icelandair
13 Dec - 14 Dec	Icelandair
06 Dec - 13 Dec	Icelandair
04 Dec - 07 Dec	Icelandair
11 Dec - 11 Jan	Icelandair
02 Dec - 12 Jan	Icelandair
02 Dec - 31 Jan	Icelandair
09 Dec - 13 Jan	Icelandair
17 Dec - 14 Jan	Aer Lingus
16 Dec - 12 Jan	Aer Lingus
28 Dec - 07 Jan	Virgin Atlantic
16 Dec - 06 Jan	Virgin Atlantic
17 Dec - 07 Jan	Virgin Atlantic
02 Dec - 12 Jan	Virgin Atlantic	direct

Also check the deals for one-way flights from London to Boston 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 London to Boston in December from 336€

Return flights