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

Return flights

05 Dec - 07 Dec	Iberia
03 Dec - 14 Dec	TAP
04 Dec - 07 Dec	TAP
03 Dec - 08 Dec	TAP
10 Dec - 14 Dec	TAP
11 Dec - 15 Dec	Aer Lingus
11 Dec - 18 Dec	Air Canada
15 Dec - 22 Dec	Icelandair
16 Dec - 23 Dec	Icelandair
12 Dec - 19 Dec	Aer Lingus
13 Dec - 12 Jan	Aer Lingus
23 Dec - 17 Jan	Air Canada
26 Dec - 10 Jan	Air Canada
28 Dec - 07 Jan	Icelandair
25 Dec - 07 Jan	Air Canada
23 Dec - 05 Jan	Icelandair
30 Dec - 06 Jan	Air Canada
23 Dec - 01 Jan	Icelandair
26 Dec - 05 Jan	Air Canada
12 Dec - 02 Jan	Delta

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 $391

Return flights