AirHint found the following cheapest return flights from San Francisco (SFO) to London (LGW) in December 2025 (see full year).

Return flights

01 Dec - 11 Dec	TAP
01 Dec - 09 Dec	TAP
29 Dec - 12 Jan	SWISS
29 Dec - 13 Jan	TAP
03 Dec - 09 Dec	TAP
01 Dec - 16 Dec	TAP
09 Dec - 22 Dec	SWISS
07 Dec - 16 Dec	Aer Lingus
02 Dec - 16 Dec	SWISS
02 Dec - 13 Dec	SWISS
29 Dec - 24 Jan	SWISS
29 Dec - 10 Jan	SWISS
03 Dec - 13 Dec	SWISS
28 Dec - 10 Jan	SWISS
25 Dec - 08 Jan	Scandinavian Airlines
29 Dec - 09 Jan	SWISS
15 Dec - 23 Dec	SWISS
09 Dec - 06 Jan	Alaska Airlines
15 Dec - 10 Jan	SWISS
14 Dec - 06 Jan	SWISS

Also check the deals for one-way flights from San Francisco 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 San Francisco to London in December from $474

Return flights