AirHint found the following cheapest return flights from Chicago (ORD) to London (LHR) in December 2026 (see full year).

Return flights

22 Dec - 28 Dec	Air Canada
22 Dec - 29 Dec	Air Canada
13 Dec - 27 Dec	TAP
16 Dec - 30 Dec	Iberia
26 Dec - 03 Jan	Air Canada
23 Dec - 30 Dec	TAP
26 Dec - 04 Jan	Air Canada
20 Dec - 29 Dec	Icelandair
16 Dec - 30 Dec	Finnair	direct
13 Dec - 27 Dec	Finnair	direct
18 Dec - 05 Jan	Austrian Airlines
22 Dec - 29 Dec	Finnair	direct
23 Dec - 30 Dec	Finnair	direct

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 $660

Return flights