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

Return flights

08 Dec - 24 Dec	British Airways
13 Dec - 29 Dec	Frontier Airlines
29 Dec - 12 Jan	Southern Airways Express
04 Dec - 11 Dec	Spirit Airlines
04 Dec - 07 Dec	Frontier Airlines
12 Dec - 19 Dec	Frontier Airlines
15 Dec - 02 Jan	Frontier Airlines
23 Dec - 28 Dec	Spirit Airlines
05 Dec - 07 Dec	Frontier Airlines
17 Dec - 04 Jan	Frontier Airlines
23 Dec - 03 Jan	Spirit Airlines
26 Dec - 02 Jan	Frontier Airlines
23 Dec - 02 Jan	Spirit Airlines
25 Dec - 01 Jan	Spirit Airlines

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

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 December from $884

Return flights