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

Return flights

02 Dec - 04 Dec	Lufthansa
12 Dec - 14 Dec	Iberia
01 Dec - 08 Dec	TAP
03 Dec - 08 Dec	TAP
10 Dec - 14 Dec	Air Canada
03 Dec - 09 Dec	Aer Lingus
09 Dec - 16 Dec	Aer Lingus
02 Dec - 10 Dec	Aer Lingus
03 Dec - 14 Dec	Aer Lingus
03 Dec - 10 Dec	United
29 Dec - 04 Jan	Icelandair
23 Dec - 03 Jan	Icelandair
23 Dec - 02 Jan	Icelandair
26 Dec - 02 Jan	Icelandair
23 Dec - 01 Jan	Icelandair
19 Dec - 03 Jan	Icelandair
29 Dec - 04 Jan	American Airlines	direct
12 Dec - 02 Jan	Air Canada
12 Dec - 01 Jan	Air Canada
11 Dec - 02 Jan	Air Canada

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.

Book a cheap hotel in London

Cheap car rent in London

Cheapest return flights from Boston to London in December from 349€

Return flights