Cheapest return flights from St. Louis to London in September from $666

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

Return flights

25 Sep - 27 Sep Frontier Airlines
25 Sep - 28 Sep Frontier Airlines
26 Sep - 28 Sep Frontier Airlines
25 Sep - 03 Oct Frontier Airlines
28 Sep - 14 Oct Spirit Airlines
21 Sep - 25 Sep Frontier Airlines
23 Sep - 30 Sep Frontier Airlines
22 Sep - 18 Oct Frontier Airlines
24 Sep - 18 Oct Southern Airways Express

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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