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

Return flights

09 Mar - 23 Mar	Icelandair
01 Mar - 07 Mar	Icelandair
03 Mar - 08 Mar	Spirit Airlines
05 Mar - 09 Mar	Icelandair
01 Mar - 08 Mar	Frontier Airlines
16 Mar - 23 Mar	Icelandair
04 Mar - 12 Mar	Icelandair
17 Mar - 23 Mar	Icelandair
31 Mar - 30 Apr	Frontier Airlines
25 Mar - 06 Apr	Lufthansa
31 Mar - 07 Apr	Frontier Airlines
14 Mar - 18 Mar	Spirit Airlines
29 Mar - 05 Apr	Air Canada
15 Mar - 17 Mar	TAP
25 Mar - 01 Apr	Lufthansa
22 Mar - 01 Apr	Icelandair
27 Mar - 05 Apr	Frontier Airlines
26 Mar - 02 Apr	Spirit Airlines
27 Mar - 06 Apr	Spirit Airlines
27 Mar - 04 Apr	SWISS

Also check the deals for one-way flights from Chicago to London in March.

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 March from 406€

Return flights