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

Return flights

17 Mar - 21 Mar	Frontier Airlines
08 Mar - 21 Mar	Frontier Airlines
27 Mar - 18 Apr	Frontier Airlines
19 Mar - 11 Apr	Porter Airlines (Canada) Ltd
21 Mar - 11 Apr	Frontier Airlines
22 Mar - 11 Apr	Frontier Airlines
06 Mar - 21 Mar	Porter Airlines (Canada) Ltd
24 Mar - 31 Mar	Frontier Airlines
17 Mar - 22 Mar	Southwest Airlines
07 Mar - 20 Mar	Frontier Airlines
13 Mar - 19 Mar	Southwest Airlines

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 $736

Return flights