Cheapest return flights from Chicago to London in September from $644

AirHint found the following cheapest return flights from Chicago (MDW) to London (LHR) in September 2025 (see full year).

Return flights

05 Sep - 09 Sep Delta
01 Sep - 09 Sep Delta
21 Sep - 30 Sep Delta
23 Sep - 30 Sep Delta
10 Sep - 24 Sep Delta
09 Sep - 17 Sep Delta
23 Sep - 01 Oct Delta
01 Sep - 01 Oct Delta
16 Sep - 23 Sep Delta
16 Sep - 30 Sep Delta
17 Sep - 30 Sep Delta
03 Sep - 07 Sep Delta
27 Sep - 04 Oct KLM
30 Sep - 07 Oct Virgin Atlantic
26 Sep - 12 Oct Porter Airlines (Canada) Ltd

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

Skyscanner

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.

Book a cheap hotel in London

Cheap car rent in London

Feel free to contact us with any feedback or request another flight research.