Cheapest return flights from St. Louis to London in September from $517

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

Return flights

28 Sep - 14 Oct Air Canada
25 Sep - 03 Oct Delta
25 Sep - 28 Sep United
23 Sep - 30 Sep Scandinavian Airlines
26 Sep - 28 Sep Delta
22 Sep - 18 Oct Air Canada
24 Sep - 18 Oct Air Canada
25 Sep - 27 Sep Finnair
21 Sep - 25 Sep Air Canada

Also check the deals for one-way flights from St. Louis 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.

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