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

Return flights

26 Aug - 09 Sep	Lufthansa
03 Aug - 12 Aug	Lufthansa
17 Aug - 26 Aug	Delta
26 Aug - 02 Sep	British Airways
12 Aug - 19 Aug	British Airways
17 Aug - 24 Aug	Delta
07 Aug - 13 Aug	Delta
03 Aug - 17 Aug	British Airways
22 Aug - 29 Aug	British Airways
18 Aug - 25 Aug	British Airways
10 Aug - 17 Aug	British Airways
24 Aug - 31 Aug	British Airways
28 Aug - 04 Sep	British Airways
28 Aug - 01 Sep	British Airways

Also check the deals for one-way flights from St. Louis to London in August.

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 St. Louis to London in August from 409€

Return flights