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

Return flights

06 Dec - 08 Dec	Air Canada
08 Dec - 10 Dec	SWISS
07 Dec - 08 Dec	Lufthansa
06 Dec - 12 Dec	TAP
02 Dec - 10 Dec	TAP
05 Dec - 06 Dec	Lufthansa
01 Dec - 10 Dec	TAP
05 Dec - 09 Dec	TAP
02 Dec - 07 Dec	TAP
03 Dec - 10 Dec	Lufthansa
11 Dec - 11 Jan	jetBlue
31 Dec - 11 Jan	Lufthansa
30 Dec - 21 Jan	jetBlue
30 Dec - 19 Jan	jetBlue
29 Dec - 10 Jan	Air Canada
29 Dec - 08 Jan	Air Canada
29 Dec - 11 Jan	Lufthansa
29 Dec - 13 Jan	Lufthansa
29 Dec - 09 Jan	Lufthansa
30 Dec - 10 Jan	Lufthansa

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 318€

Return flights