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

Return flights

05 Dec - 11 Dec	Air Canada
06 Dec - 11 Dec	Air Canada
04 Dec - 11 Dec	Air Canada
05 Dec - 10 Dec	Air Canada
10 Dec - 15 Dec	Air Canada
06 Dec - 13 Dec	Air Canada
01 Dec - 08 Dec	Air Canada
01 Dec - 14 Dec	Air Canada
07 Dec - 14 Dec	Air Canada
11 Dec - 24 Dec	Air Canada
29 Dec - 07 Jan	SWISS
17 Dec - 06 Jan	Lufthansa
29 Dec - 10 Jan	Lufthansa
28 Dec - 07 Jan	Air Canada
29 Dec - 07 Jan	Virgin Atlantic	direct
16 Dec - 04 Jan	TAP
17 Dec - 06 Jan	Virgin Atlantic	direct
16 Dec - 03 Jan	Icelandair
13 Dec - 03 Jan	Icelandair
30 Dec - 04 Jan	Air France	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 354€

Return flights