AirHint found the following cheapest return flights from Washington (DCA) to London (LGW) in December 2025 (see full year).

Return flights

03 Dec - 10 Dec	Icelandair
03 Dec - 13 Dec	Icelandair
12 Dec - 17 Dec	Icelandair
11 Dec - 15 Dec	jetBlue
12 Dec - 15 Dec	jetBlue
05 Dec - 09 Dec	TAP
15 Dec - 19 Dec	Icelandair
23 Dec - 02 Jan	Icelandair
16 Dec - 03 Jan	Icelandair
12 Dec - 13 Jan	TAP
29 Dec - 06 Jan	TAP
28 Dec - 06 Jan	TAP
18 Dec - 25 Dec	TAP
14 Dec - 23 Dec	TAP
13 Dec - 31 Dec	TAP
19 Dec - 01 Jan	Air Canada
20 Dec - 10 Jan	TAP

Also check the deals for one-way flights from Washington 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 Washington to London in December from $807

Return flights