AirHint found the following cheapest return flights from London (LON) to Boston (BOS) in December 2026 (see full year).

Return flights

05 Dec - 12 Dec	Icelandair
02 Dec - 07 Dec	Icelandair
11 Dec - 20 Dec	Icelandair
11 Dec - 29 Dec	Lufthansa
11 Dec - 28 Dec	Lufthansa
02 Dec - 07 Dec	Finnair	direct
12 Dec - 16 Dec	Icelandair
28 Dec - 04 Jan	Air Canada
14 Dec - 28 Dec	Air Canada
11 Dec - 27 Dec	SWISS
17 Dec - 29 Dec	Lufthansa
28 Dec - 01 Jan	Air Canada
28 Dec - 03 Jan	Air Canada
27 Dec - 01 Jan	Air Canada
27 Dec - 03 Jan	Iberia
25 Dec - 02 Jan	Iberia
26 Dec - 03 Jan	Iberia
25 Dec - 01 Jan	Iberia
26 Dec - 02 Jan	Iberia
26 Dec - 01 Jan	Iberia

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 353€

Return flights