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

Return flights

14 Dec - 14 Jan	TAP
04 Dec - 15 Dec	TAP
03 Dec - 09 Dec	TAP
04 Dec - 06 Dec	TAP
11 Dec - 15 Dec	TAP
10 Dec - 15 Dec	TAP
04 Dec - 07 Dec	TAP
10 Dec - 16 Dec	TAP
02 Dec - 10 Dec	TAP
07 Dec - 15 Dec	TAP
06 Dec - 13 Dec	Aer Lingus
12 Dec - 13 Jan	Aer Lingus
10 Dec - 25 Jan	Air Canada
11 Dec - 25 Jan	Air Canada
10 Dec - 12 Jan	Aer Lingus
15 Dec - 20 Jan	Virgin Atlantic	direct
31 Dec - 07 Jan	Lufthansa
14 Dec - 31 Jan	Aer Lingus
14 Dec - 14 Jan	jetBlue	direct
14 Dec - 31 Jan	jetBlue	direct

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 350€

Return flights