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

Return flights

21 Jan - 30 Jan	TAP
22 Jan - 26 Jan	TAP
23 Jan - 28 Jan	TAP
22 Jan - 30 Jan	TAP
21 Jan - 28 Jan	TAP
23 Jan - 25 Jan	TAP
29 Jan - 09 Feb	TAP
30 Jan - 09 Feb	TAP
14 Jan - 20 Jan	TAP
23 Jan - 27 Jan	TAP
20 Jan - 27 Jan	TAP
09 Jan - 12 Jan	Icelandair
25 Jan - 14 Feb	Icelandair
15 Jan - 07 Feb	Icelandair
20 Jan - 12 Feb	Icelandair
21 Jan - 01 Feb	Icelandair
19 Jan - 14 Feb	Icelandair
26 Jan - 21 Feb	Icelandair
22 Jan - 14 Feb	Icelandair
24 Jan - 14 Feb	Icelandair

Also check the deals for one-way flights from Washington to London in January.

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 January from $424

Return flights