AirHint found the following cheapest return flights from Washington (IAD) to London (LGW) in December 2026 (see full year).

Return flights

11 Dec - 20 Dec	TAP
17 Dec - 24 Dec	Icelandair
17 Dec - 27 Dec	Icelandair

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 $804

Return flights