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

Return flights

09 Dec - 15 Dec	Icelandair
05 Dec - 11 Dec	Icelandair
01 Dec - 08 Dec	Icelandair
12 Dec - 22 Jan	Frontier Airlines
02 Dec - 10 Dec	Icelandair
03 Dec - 10 Dec	Icelandair
04 Dec - 08 Dec	Icelandair
08 Dec - 11 Dec	Icelandair
01 Dec - 15 Jan	Icelandair
03 Dec - 09 Dec	Icelandair
12 Dec - 15 Jan	Frontier Airlines
05 Dec - 12 Dec	Icelandair
14 Dec - 27 Jan	Icelandair
31 Dec - 07 Jan	Icelandair
31 Dec - 24 Jan	Icelandair
30 Dec - 11 Jan	Icelandair
01 Dec - 07 Dec	Scandinavian Airlines
15 Dec - 22 Jan	Icelandair
28 Dec - 17 Jan	Icelandair
15 Dec - 07 Jan	Icelandair

Also check the deals for one-way flights from Chicago 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 Chicago to London in December from 398€

Return flights