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

Return flights

12 Dec - 15 Jan	Frontier Airlines
02 Dec - 09 Dec	Icelandair
08 Dec - 14 Dec	Icelandair
07 Dec - 13 Dec	Icelandair
02 Dec - 14 Dec	Icelandair
09 Dec - 14 Dec	Icelandair
07 Dec - 14 Dec	Icelandair
12 Dec - 11 Jan	Spirit Airlines
03 Dec - 09 Dec	Icelandair
05 Dec - 12 Dec	Icelandair
11 Dec - 13 Jan	Icelandair
01 Dec - 08 Dec	Icelandair
06 Dec - 12 Dec	Icelandair
08 Dec - 14 Jan	Icelandair
02 Dec - 30 Jan	Icelandair
31 Dec - 24 Jan	Icelandair
30 Dec - 14 Jan	Icelandair
29 Dec - 19 Jan	Icelandair
31 Dec - 18 Jan	Icelandair
29 Dec - 13 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 $435

Return flights